The U.K. Navy issued a rare warning to mariners that higher tensions in the Middle East could impact shipping, including through the Strait of Hormuz.

“UKMTO has been made aware of increased tensions within the region which could lead to an escalation of military activity having a direct impact on mariners,” the June 11 advisory said. “Vessels are advised to transit the Arabian Gulf, Gulf of Oman and Straits of Hormuz with caution.”

Shipping has often been risky in the Middle East, but UKMTO — which acts as a liaison between the navy and commercial shipping — rarely puts out general warnings such as this one. In May, it also issued a warning about electronic interference around Hormuz, a waterway that handles around 26% of the world’s oil trade.

The UKMTO’s alert didn’t specify the nature of the anticipated tensions.

There’s been a steady backdrop of threats to vessels over recent years. The U.S. and Iran are continuing talks about Tehran’s nuclear program, the future of which remains uncertain. Israel has also been attacking Yemen’s Houthi rebel group, which in turn has been menacing shipping in the Red Sea. Under the first Trump administration, Iran also started a campaign of hijacking vessels.

American and Iranian navy ships nearly crashed on Monday after three speedboats zoomed past US warships at high speed.

The US Navy said one of three of the Guard fast craft raced head-on at the Cyclone-class patrol ship USS Sirocco before changing course.

The Navy warship had to fire a warning flare to wave off the Iranian Revolutionary Guard speedboat coming straight at it before turning head on during a tense encounter in the strategic Strait of Hormuz, officials said Tuesday.

The incident on Monday involving the Guard and the Navy comes as tensions remain high over stalled negotiations over Iran’s tattered nuclear deal with world powers and as Tehran enriches uranium closer than ever to weapons-grade levels under decreasing international oversight.

The US navy was patrolling the Strat of Hormuz, a strategically important narrow passage off the shores of Iran in which oil tankers travel. The Iranian boat can be seen approaching in the distance, breaking away from the rest of the trio

The Iranian speedboat is pictured in the distance racing towards the US warship in the Gulf

The speedboat veered off after the US navy fired a warning flare moments before it turned

Meanwhile, the United Nations’ nuclear watchdog said Iran now plans to enrich uranium through a second set of advanced centrifuges at its underground Fordo facility amid the standoff.

The Cyclone-class patrol ship USS Sirocco and Spearhead-class expeditionary fast transport USNS Choctaw County found themselves in the close encounter with three Iranian fast boats while coming through the Strait of Hormuz to enter the Persian Gulf, the Navy said.

In a video released by the Navy’s Bahrain-based 5th Fleet, a high-speed Guard Boghammar is seen turning head-on toward the Sirocco.

In this image from a video made available by the US Navy, a boat of Iran’s Islamic Revolutionary Guard Corps Navy is seen speeding close to the patrol coastal ship USS Sirocco and expeditionary fast transport USNS Choctaw County in the Strait of Hormuz

The Sirocco repeatedly blows its horn at the Boghammar, which turns away as it closes in. The flare shot can be heard, but not seen, as the Boghammar passes the Sirocco with the Iranian flag flying above it.

The Navy said the Boghammar came within 50 yards of the Sirocco, raising the risk of the vessels running into each other. The overall encounter lasted about an hour, the Navy said.

The Guard’s ‘actions did not meet international standards of professional or safe maritime behavior, increasing the risk of miscalculation and collision,’ the Navy said.

Iran did not immediately acknowledge the incident in the strategic waterway – a fifth of all traded oil passes through the strait.

The Navy separately told The Associated Press that this marked the second so-called ‘unsafe and unprofessional’ incident it had with Iran in recent months.

On March 4, three Guard ships had a tense encounter for over two hours with Navy and US Coast Guard vessels as they traveled out of the Persian Gulf through the strait, the Navy said.

The US Navy said one of three of Iran’s navy speedboats, pictured, zoomed at the Cyclone-class patrol ship USS Sirocco before changing course at the last moment when it fire a flare

In that incident, the Guard’s catamaran Shahid Nazeri came within 25 yards of the USCGC Robert Goldman, the Navy said.

Shahin Gobadi of the Foreign Affairs Committee of the National Council of Resistance of Iran, affiliated with opposition groups, said ‘creating chaos’ in the Persian Gulf and throughout the region has been ‘a pillar of survival and statecraft of the Iranian regime’ since its early days.

‘One cannot find any protracted period that the Iranian regime has not been directly involved in an act of piracy or creating a crisis in the region throughout the past 40 years,’ he said.

Gobadi added there had been a major uptick in executions and suppression since the installment of Ebrahim Raisi as the president by the supreme leader in 2021.

File photo: The speedboat raced head-on towards the Cyclone-class patrol ship USS Sirocco before changing course

File photo: US Navy sailors stand guard aboard the USS Sirocco patrol ship while docked at the US 5th Fleet Command in Bahrain’s capital Manama on December 17, 2019

‘The two US Coast Guard cutters issued multiple warnings via bridge-to-bridge radio and deployed warning flares,’ the Navy said.

The Navy did not elaborate on why it did not announce the previous incident, particularly since a larger vessel came even closer to an American warship.

However, that was just as a deal in Vienna between Iran and world powers on restoring the nuclear deal looked possible, before the talks broke down.

Iran and world powers agreed in 2015 to the nuclear deal, which saw Tehran drastically limit its enrichment of uranium in exchange for the lifting of economic sanctions.

in 2018, then-President Donald Trump unilaterally withdrew America from the accord, raising tensions across the wider Middle East and sparking a series of attacks and incidents.

Talks in Vienna about reviving the deal have been on a ‘pause’ since March. Since the deal’s collapse, Iran has been running advanced centrifuges and rapidly growing stockpile of enriched uranium.

Pictured: Iranian Presidency, President Ebrahim Raisi. Iran is working to purify uranium at new sites that could enable it to build a nuclear bomb in a matter of weeks, according to Israel

Earlier this month as well, Iran removed 27 surveillance cameras of the UN’s International Atomic Energy Agency. The agency’s head warned it could deal a ‘fatal blow’ to the nuclear deal.

On Tuesday, the IAEA said its inspectors verified Iran was preparing to enrich uranium through a new cascade of 166 advanced IR-6 centrifuges at its underground Fordo facility.

Already, Iran has one cascade of IR-6s operating at Fordo, near the holy Shiite city of Qom, some 55 miles southwest of Tehran. They enrich up to 20% purity.

The IAEA said Iran has not told it yet the level at which the second cascade will be enriching. Iran has yet to publicly acknowledge the new cascade.

The 2015 nuclear deal prohibited all enrichment at Fordo. Shielded by mountains, the facility is ringed by anti-aircraft guns and other fortifications.

It is about the size of a football field, large enough to house 3,000 centrifuges, but small and hardened enough to lead US officials to suspect it had a military purpose when they exposed the site publicly in 2009.

Amid the tensions, Israel is suspected of carrying out a series of attacks in and outside of Iran targeting the country, including the killing of the architect of its one-time military nuclear program with a remote-controlled machine gun.

A man celebrates with Israeli flags as Israeli Air Force planes fly in formation. The Israeli airforce will drill striking targets outside the borders of Israel, in preparation for nuclear talks failing between the West and Iran

Israel’s defence minister Benny Gantz warned that Iran is building new underground facilities to purify uranium in advanced centrifuges

On Tuesday, the state-run IRNA news agency quoted the prosecutor of Iran’s southeastern Sistan and Baluchistan province as alleging three people arrested in April there on suspicion of working with Israel’s Mossad intelligence agency wanted to kill Iranian nuclear scientists.

It’s unclear why the three would have been in Sistan and Baluchistan, which has no nuclear sites.

The restive province that borders Afghanistan and Pakistan faces sporadic attacks from armed insurgent groups.

The news comes after exiled opposition sources accused Iran of setting up a committee to deceive the UN atomic watchdog and build devices capable of denoting nuclear weapons in secret.

The National Council of Resistance of Iran (NCRI) accused the Islamic Republic of developing so-called ‘exploding-bridgewire detonators’ by sending the UN forged documents that stated they were needed for oil drilling.

The devices can be used for detonating implosion-type nuclear weapons, and are monitored by the UN’s International Atomic Energy Agency (IAEA).

NCRI foreign affairs committee member Shahin Gobadi said Iran’s intention was to ‘hoodwink the international community’ to ‘prevent the exposure of its ominous objective of obtaining the nuclear bomb’.

Tehran had forged documents and exchanged communication between the Oil Ministry and the Defense Ministry to prove that the exploding-bridgewire detonators (EBWs) were produced and used for oil drilling, according to the NCRI.

This satellite photo from Planet Labs Inc. shows Iran’s Natanz nuclear facility on April 7, 2021

Centrifuge machines at the Natanz Uranium Enrichment Facility. The IAEA said in a March report that Iran had installed or planned to install a total of three IR6 cascades, amounting to around 660 machines, at new underground sites near Natanz

But it said the National Iranian Drilling Company has not received even one of the EBW detonators produced by the Ministry of Defence.

On June 8, the UN passed a draft resolution criticizing Iran for failing to fully explain uranium traces at undeclared sites.

Israel accused Iran of purifying uranium at sites under construction near its Natanz nuclear plant.

In 2002, the NCRI previously exposed a secret Uranium enrichment site in Natanz and a heavy water reactor in Arak.

The United States, France, Britain and Germany put the draft resolution to the board, which passed on Wednesday.

The bill is the first to criticize Iran since June 2020, when tensions were running hot over the attempted revival of the nuclear deal.

This satellite image from Maxar Technologies shows an overview of launch pad activity at Imam Khomeini Space Center southeast of Semnan, Iran on June 14, 2022. Iran appeared to be readying for a space launch as satellite images showed a rocket on a rural desert launch pad, just as tensions remain high over Tehran’s nuclear programme

The foreign ministries of the four Western nations issued a joint statement condemning Iran’s ‘insufficient cooperation with the IAEA on serious and outstanding safeguards issues’, relating to its nuclear activities.

Iranian authorities have also acknowledged plans to test its new solid-fueled rocket after satellite photos showed preparations at a desert launch pad previously used in the program.

The Islamic Republic will launch its satellite-carrying Zuljanah rocket twice more after conducting a previous launch, the state-run IRNA news agency quoted Defence Ministry spokesman Ahmad Hosseini as saying.

One set of images showed a rocket on a transporter, preparing to be lifted and put on a launch tower. A later image showed the rocket apparently on the tower.

Though it isn’t clear when the launch will take place, erecting a rocket typically means a launch is imminent. NASA fire satellites, which detect flashes of light from space, did not immediately see any activity over the site late Tuesday night into Wednesday.

A U.S. Coast Guard cutter fired warning shots from its .50-caliber machine gun at a large group of armed Iranian speedboats that were quickly approaching American ships passing through the Strait of Hormuz on Monday morning.

In a briefing with reporters, Pentagon Press Secretary John Kirby said that the group of 13 fast boats were part of Iran’s Islamic Revolutionary Guard Corps Navy, or IRGCN. He called the encounter “significant.”

The boats “conducted unsafe and unprofessional maneuvers, and failed to exercise due regard for the safety of U.S. forces as required under international law, while operating in close proximity to U.S. naval vessels that were transiting the Strait of Hormuz,” Kirby said.

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The U.S. Navy said in a statement that the Iranian boats were fast in-shore attack craft, a type of speedboat that is armed with machine guns.

Two Iranian Islamic Revolutionary Guard Corps Navy fast in-shore attack craft conducted maneuvers in close proximity to USCGC Maui as it transits the Strait of Hormuz, May 10, 2021 (U.S. Navy)

This represents the second time in two weeks that American ships have fired warning shots at Iranian speedboats. The Navy last month said its ships encountered Iranian speedboats on April 26 in international waters in the north Arabian Gulf and, after issuing several warnings, fired warning shots.

Six U.S. Navy and Coast Guard vessels, including the guided missile cruiser Monterey, were escorting the guided missile submarine Georgia when they encountered the Iranian ships, Kirby said, adding that the ships were on their way to the Persian Gulf.

The other American ships involved in the encounter were the Navy patrol ships Thunderbolt, Hurricane and Squall, and the Coast Guard patrol boats Maui and Wrangell.

Kirby said the Iranian boats approached the American ships at high speed, coming as close as 150 yards from them.

The Navy said that two of the 13 Iranian speedboats broke away from the larger group and moved to the opposite side of the U.S. formation. Those two speedboats approached the Maui and Squall from behind, the Navy said, at more than 32 knots, or nearly 37 miles per hour.

The Navy said the two Iranian boats had their weapons uncovered and manned. The other 11 Iranian boats remained in their original position, the service said, putting the U.S. ships between two groups of Iranian boats.

Kirby said the U.S. ships followed “all the appropriate and established procedures” and made several attempts to communicate with the Iranian boats and dissuade them from their approaches.

The Navy said that the Maui and Squall made multiple bridge-to-bridge verbal warnings, five “acoustic device” warnings, and five short horn blasts. The service said that is the internationally recognized signal for danger when trying to prevent collisions at sea.

When those efforts were unsuccessful, Kirby said, the Maui fired two volleys of warning shots from its .50-cal, totaling about 30 shots in all. The first volley was fired when the ships were within 300 yards, the Navy said, and the second when they were within 150 yards.

After the second volley of warning shots, the 13 Iranian ships broke off contact.

“The U.S. crews operated with distinct professionalism and superior seamanship,” the Navy said. “As professional mariners, we expect the IRGCN to operate with due regard for the safety of all vessels as required by international law.

“Our Navy will continue to fly, sail and operate anywhere international law allows while promoting the rules-based international order throughout the region,” the service continued. “In support of international norms, the U.S. is not an aggressor. Our naval forces remain postured in a non-provocative manner that exemplifies professionalism, incentives adherence to international law and customs, and persuades others to emulate our actions. Our forces are trained, however, to conduct effective defensive measures when necessary.”

Kirby said he could not comment on how often such encounters have happened in the Strait of Hormuz, but added that this kind of encounter is dangerous in close quarters.

“It’s an international waterway and, of course, when you’re in the strait, there are certain limits to your ability to maneuver,” he said. “It is a choke point in the region. So it’s not insignificant that this kind of dangerous, unsafe and unprofessional behavior occurred there.”

Kirby said it is not yet known whether video of this encounter exists. But videos of incidents have been released after a classification review, he said.

Kirby declined to comment on the Iranian boats’ possible motivations for this encounter, or at what point U.S. ships might fire directly upon Iranian vessels.

But, he said, U.S. vessels have the right of self-defense and the means to defend themselves and their crews.

“Sadly, harassment by the IGRC Navy is not a new phenomenon,” Kirby said. “It is something that all our commanding officers and crews of our vessels are trained for, when serving in the Central Command area of responsibility, particularly in and around the Gulf.”

Kirby said that the two recent incidents show that American crews “are very stringent about following the proper procedures for providing warnings verbally first and then, if need be, through the use of warning shots to try to change and to mitigate the Iranian behavior.”

But, he said, such behaviors are unsafe and unprofessional.

“This kind of activity is the kind of activity that can lead to somebody getting hurt, and can lead to a miscalculation in the region,” Kirby said. “And that doesn’t serve anybody’s interests.”

The Monterey recently discovered and seized an arms shipment aboard a “stateless dhow” it intercepted in the northern Arabian Sea.

That arms seizure operation, which began last Thursday and concluded Friday, netted a cache of Chinese-made Kalashnikov-style assault rifles, sniper rifles, heavy machine guns, and rocket-propelled grenade launchers.

While the Navy did not say where the shipment likely originated, similar arms caches interdicted by U.S. and other allied forces in the region were later described to be headed for Yemen.

— Stephen Losey can be reached at stephen.losey@military.com. Follow him on Twitter @StephenLosey.

Related: US Navy Fires Warning Shots at Iranian Fast Attack Craft

Iran’s Revolutionary Guard has staged a mock attack on a fake aircraft carrier in the Strait of Hormuz, in a drill which saw two US bases briefly put on missile alert.

Key points: Iranian commandos boarded the carrier during the exercise, called Great Prophet 14

Iran frequently practises for possible attacks on US aircraft carriers

American troops were put on alert at bases in Abu Dhabi and Qatar

The Great Prophet 14 exercise saw Guard commandos abseil down onto the vessel from a helicopter, and anti-aircraft guns open fire on a target drone near the port city of Bandar Abbas.

Iranian state television footage also showed a variety of missiles being fired from fast boats, trucks, mobile launchers and a helicopter, some targeting the fake carrier.

A commander said the Revolutionary Guard, a force answerable only to Supreme Leader Ayatollah Ali Khamenei, also planned to fire “long-range ballistic missiles” during the drill, which will continue throughout Wednesday.

Iranian speedboats circled the fake carrier during the exercise in the Strait of Hormuz. (AP: Sepahnews )

Ballistic missile fire detected from the drill resulted in American troops being put on alert at Al-Dhafra Air Base in Abu Dhabi in the United Arab Emirates and Al-Udeid Air Base, the forward headquarters of the US military’s Central Command, in Qatar.

Troops sought cover during that time.

“The incident lasted for a matter of minutes and an all clear was declared after the threat … had passed,” said US Army Major Beth Riordan.

Both bases are hundreds of kilometres away from where Iran positioned the replica aircraft carrier.

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Al-Dhafra is also temporarily home to five French-built Rafale fighter jets on their way to India for that country’s air force.

While Iran’s naval forces are dwarfed by the US Navy, its commanders practise swarm tactics aimed at overwhelming US carriers.

The replica used in the drill resembled the Nimitz-class carriers that the US Navy routinely sails into the Persian Gulf from the Strait of Hormuz, the narrow mouth of the waterway through which 20 per cent of the world’s oil trade passes.

The exercise had been expected, as satellite photos released on Monday showed the fake carrier being moved into place by a tugboat.

A black-and-white satellite photo taken on Tuesday by Colorado-based firm Maxar Technologies showed damage to the replica vessel’s bow and several of its fake jet fighters.

“Our policies to protect the vital interests of the dear nation of Iran are defensive, in the sense that we will not invade any country from the beginning, but we are completely aggressive in tactics and operations,” Iranian general Hossein Salami said.

“What was shown today at this exercise at the level of aerospace and naval forces was all offensive.”

During the exercise called Great Prophet 14, missiles and anti-aircraft guns were launched. (SP: Sepahnews )

State TV footage also showed scuba forces underwater, followed by a cutaway to a blast hole just above the waterline on the replica carrier.

That appeared to be a not-so-subtle reminder of US accusations last year that Iran used limpet mines to attack oil tankers.

Iran has repeatedly denied the claims, though footage captured by the American military at the time showed Guard members removing an unexploded mine from one vessel.

The USS Nimitz carrier entered Middle Eastern waters late last week from the Indian Ocean and is likely to replace the USS Dwight D Eisenhower in the Arabian Sea.

It remains unclear when or if the Nimitz will pass through the Strait of Hormuz.

A history of hate Photo shows On a sign post, one sign is facing right has ‘Iran’ written on it and the other has ‘USA’ Iran and the United States haven’t had formal diplomatic relations for decades, and at times appear on the brink of war. But why?

The USS Abraham Lincoln, deployed last year as tensions initially spiked, spent months in the Arabian Sea before heading through the strait.

The Eisenhower came through the strait early last week.

The US Navy has stressed the strait is an international waterway crucial to global shipping and energy supplies.

Commander Rebecca Rebarich, a spokeswoman for the US Navy’s Bahrain-based 5th Fleet, described the Iranian exercise as “attempting to intimidate and coerce”.

“While we are always watchful of this type of irresponsible and reckless behaviour by Iran in the vicinity of busy international waterways, this exercise has not disrupted coalition operations in the area nor had any impacts to the free flow of commerce in the Strait of Hormuz and surrounding waters,” she said.

Tensions have persisted between the two countries over the past year.

A series of escalating incidents last year led to an American drone strike killing a top Iranian general in Baghdad.

Tehran responded to that strike by firing ballistic missiles at US and allied bases in Iraq.

The US has also been arguing to extend an UN weapons embargo on Tehran that is due to expire in October, and a recent incident over Syria involving an American jet fighter approaching an Iranian passenger plane did not calm fears in the region.

AP/ABC