Two of Russia’s largest pharmacy chains suspended operations across several regions on Tuesday following cyberattacks that disrupted digital infrastructure and brought their nationwide networks offline.

The closures at Neopharm and Stolichki have impacted over 1,100 pharmacy locations in more than 80 cities across central Russia since they began, leaving customers unable to access prescriptions and medication reservations, loyalty programs or point-of-sale systems.

Stolichki, the larger of the two networks with more than 1,000 locations, operates across Moscow, St. Petersburg and the the Leningrad, Tula and Vladimir regions.

Notices posted to the company’s website apologized for the disruption and promised that “unavailable features would be restored soon.”

Neopharm, which runs over 110 pharmacies in Moscow and St. Petersburg, experienced similar shutdowns. Employees were sent home as IT systems remained nonfunctional.

Initially, the chains cited “technical reasons” for the outages. Stolichki later confirmed that the suspensions were caused by a cyberattack and that restoration efforts were underway.