Russia’s state communications watchdog Roskomnadzor confirmed Wednesday that it is restricting voice and video calls on WhatsApp and Telegram, calling it an anti-fraud measure to protect citizens.

“Calls on these foreign messaging platforms are partially restricted to counter criminal activity,” the state-run news agency quoted Roskomnadzor as saying in a statement. “Nearly all such fraudulent calls have shifted to foreign messengers, which refuse to ensure the safety of Russian users.”

On Sunday, Russians across the country began reporting problems making voice and video calls via WhatsApp and Telegram. However, it was not immediately clear how widespread the disruptions were, as The Moscow Times has managed to make calls to Russian users in various regions through the messengers without issue.

Roskomnadzor’s statement confirmed early reports that the Russian government was “selectively blocking” calls on the two messaging platforms, which allegedly began at the start of August.

According to the state watchdog, WhatsApp and Telegram have become the primary channels for call-based scams, extortion and recruitment into acts of terrorism and sabotage over the past year. Russia’s Digital Development Ministry said calls on the messaging apps could be restored if they comply with Russian law.

“No other functions of these apps are being limited,” Roskomnadzor was quoted as saying by TASS.