Drones have struck a major data centre belonging to Russia’s largest search engine and AI company Yandex, according to a company statement.

The company said the attack targeted a facility in Russia’s Ryazan region, causing a fire and forcing Yandex to fully suspend the centre’s operations.

Yandex said it was dealing withthe consequences and restoring affected services. It said its core consumer services were not affected.

On the website ‌of its Yandex Cloud ​service, the company said there ‌were problems with ⁠the electricity supply at ⁠one data centre “zone”, and recommended customers use ‌other zones.

Yandex runs YandexGPT, one ‌of Russia’s leading generative AI models, and its search engine dominates the domestic market in Russia, far outstripping international competitors like Google.

Though there was no immediate confirmation of the attack from Kyiv, it appears to the be the first confirmed major Ukrainian drone strike on a Russian data centre.

It follows a wave of Russian attacks on Ukrainian data centres in recent weeks.

Russia’s defence ministry said its forces had carried out a “massive strike” on military-industrial facilities in Kyiv and other Ukrainian ‌regions, using high-precision land-, sea- and air-launched weapons, as well as drones.

Ukraine’s air force said it had downed just over 80 per cent of the 46 jet-powered drones launched by Russia, a sharp increase from recent weeks when, on average, air defences took down 50 per cent to 60 per cent.

Since the summer, Russia has used increasing numbers of the new high-velocity drones in round-the-clock attacks on Kyiv and other cities, with Ukraine’s air defences struggling to cope with their speed.

The air force did not explain the jump in the interception rate and did not immediately respond to requests for comment.

Ukrainian officials and military intelligence shared warnings of the upcoming attacks on Wednesday, and many Kyiv residents took shelter in the city’s underground metro stations.

Several loud explosions reverberated through the capital during the night.

“The metro is better because we ​live on the 9th floor of a high-rise, and it’s really scary when you’re on ‌the 9th floor and missiles are flying at you,” Lesia, a 49-year-old ​Kyiv resident, told Reuters.

Ukrainian officials said Russian ballistic missiles as well as drones had targeted Kyiv.

Russia pounded Ukraine with waves of missiles and drones in one of its most “vile strikes” on Wednesday, president Volodymyr Zelensky said, killing at least 25 people, including children, and damaging industrial facilities and energy infrastructure.

The heaviest death toll was in Pryluky in Ukraine’s northern Chernihiv region, where a Russian missile obliterated a five-storey residential building.

Zelensky said 19 people died in the attack, including five children. Zelensky said 25 people had been killed in the strikes throughout the country, with 100 injured. Interior minister Ivan Vyhivskyi put the death toll at 28.

The president noted that the attacks coincided with Russian president Vladimir Putin’s birthday. “This is the kind of birthday present that Putin gave himself: the killing of children, the killing of people,” Zelensky said in his nightly video address

Russia’s defence ministry said on Wednesday that its forces had struck a vessel it said was heading to the Ukrainian Black Sea port of Odesa with a cargo for the Ukrainian military. The statement on ⁠Telegram gave no further details of the strike.

The ministry also said Russian drones had hit infrastructure in Ukrainian ports, without elaborating.

South Korea’s foreign ministry said on Thursday the government would take a legal action over any illegal fuel shipments to Russia if they were confirmed, following a media report analysing port records and ship-tracking data.

The ‌ministry said it had not confirmed ‌whether South Korean fuel, including diesel, had been exported ⁠to Russia.

It added that exports of some products such as diesel and jet fuel for commercial purposes, referred to in the Guardian report, were not included in a South Korean exports control list to Russia.

Bulgaria has halted its search for the missing crew of a ship that sank after being hit by a drone about 70 nautical miles off its coast, officials say.

Early on Tuesday, two ships were ⁠hit in a drone attack in the Black Sea exclusive economic zone of Bulgaria, a Nato member.

One ship sank and the other was damaged. The crew of the damaged ship were rescued, but the crew of the sunken one remain missing.

Vice-Admiral Rumen Nikolov of the Maritime Administration Executive Agency said 12 crew members were believed to have been on board the ship that sank, all of them from Syria.

The rescue operation will not resume, he added. “There are no traces of ​the ⁠sailors from the first ship, and there will be none. There is also no information about drone remains,” he told reporters.

It was not immediately clear who carried out the attack involving air and sea drones ​in ⁠waters off the coastal town of Byala in ‌eastern Bulgaria, but there are growing concerns about hybrid attacks by Russia as it wages war in Ukraine.

“If we look at the nature of the cargo and the direction in which the ships were moving, then logically speaking, the result argues in favour of Russia,” Prime Minister Rumen Radev said.

Turkish president Recep Tayyip Erdogan has called Russia’s Vladimir Putin, telling him Turkey is ready to contribute to efforts to begin direct talks between Russia and Ukraine, and stressing the importance of safety of navigation in the Black Sea, according to Erdogan’s office.

The two presidents discussed bilateral relations, as well as regional and global issues, Turkey’s government said.

Erdogan also congratulated Putin on his birthday and his party’s success in the latest Russian parliamentary elections, the office said.