Yandex has lost a third major data centre in four days. The Russian tech company said on Sunday that a drone attack had left its site in the Vladimir region, east of Moscow, out of service, Reuters reported.

Nobody was hurt, Yandex said, though some of its services are down for users. The report does not name who sent the drones, and we have not independently checked the scale of the damage.

Three of the company’s five large data centres have now been hit. Besides Vladimir, Yandex runs sites in Sasovo, Kaluga, Ivanteevka, and Mytishchi, according to DatacenterDynamics.

The first strike came on Thursday, when a fire broke out at the Sasovo hub in the Ryazan region and work there stopped. On Friday, Ukrainian drones partly disabled the Kaluga site, southwest of Moscow.

Ukraine’s president, Volodymyr Zelenskiy, confirmed the Kaluga attack and framed it as payback for Russian strikes. Also, Kyiv has leaned on cheap long-range drones to reach targets deep inside Russia this year.

The Sasovo loss matters most for the company’s AI work. That hub houses two of the three supercomputers Yandex relies on to build its YandexGPT model. The company has said it does not yet know whether the equipment there can be saved.

Firms that run on Yandex’s cloud have been hit as well. After the Sasovo strike, the websites of Russian Railways and mobile operator MegaFon went down, according to independent outlet Meduza.

Yandex said rival cloud firms had agreed to let its clients transfer their data and apps quickly.

The attacks on Yandex follow a month of Russian strikes on Ukrainian data centres and telecoms sites, some in central Kyiv.

One of those attacks cut internet access for about 100,000 homes, and Ukraine’s digital minister told Reuters the country is moving its digital systems underground.

Data centres have also become military targets in the Middle East. In March, Iran’s Revolutionary Guards listed 18 US tech firms as targets. The UAE is now splitting up its Stargate data centre campus after Iran named it as one.

Back in Moscow, Yandex shares fell more than 4% after the Kaluga strike. Maryana Lazaricheva, head of equity research at T-Investments, told Reuters that Yandex could shift some work to its remaining sites. If the attacks go on, she said, that option will disappear.