Ukrainian drones struck a Yandex data center in Sasovo, Russia’s Ryazan Oblast, and the Gazprom Neftekhim Salavat oil refinery in Bashkortostan overnight, sparking fires.

In Sasovo, the attack damaged one of Yandex’s largest data centers, causing power outages and widespread disruptions to its cloud services.

The strike followed a series of Russian attacks on Ukrainian data centers.

A fire also broke out at the Sasta machine-tool plant, which shares the site with the data center and supplies Russia’s defense industry.