“It took more than 16 hours to extinguish a fire in a Kharkiv construction hypermarket caused by targeted Russian strikes,” he said on Telegram. “Russian shelling killed 12 people and injured 43 others”.

Forensics experts and investigators were still working to identify bodies in the ruins of the Epitsentr DIY shop in the northeastern outskirts of the city, Klymenko said.

Earlier, the Kharkiv regional governor Oleg Synegubov said two of the people who had been killed worked in the hypermarket, adding that the city had been under “massive rocket fire all day”.

Synegubov said there was “no contact with some of the staff” and “according to our information, visitors could still be in the building”.

Still wearing her uniform, Lyubov, a cleaner at the shop, recalled how she escaped the building.

“It happened all of a sudden. We didn’t understand at first, everything went dark and everything started falling on our heads,” she said.

“It was good that my phone lit up, thanks to the flashlight I found where to go, but in front of us everything was burning already.”

Ukrainian President Volodymyr Zelensky condemned the daylight attack on an “obviously civilian” target.

“Only madmen like Putin are capable of killing and terrorising people in such a vile way,” he said, referring to the Russian president, who ordered his troops into Ukraine in February 2022.

Russia’s TASS state news agency cited a security source claiming that the hypermarket missile strike destroyed a “military store and command post” inside the shopping centre.

“I am appealing to the leaders of the world … to President Biden, the leader of the United States, and to President Xi, the leader of China … Please support the peace summit with your personal leadership and participation,” Zelensky said.

Bern has said it has invited 160 delegations but that Russia will not attend.

China has said it supports an international peace conference that is recognised by both Russia and Ukraine.

04:28

‘I just want him back’: Indian national dies after reportedly being tricked into fighting for Russia

‘I just want him back’: Indian national dies after reportedly being tricked into fighting for Russia

For Russia, “it is a pleasure to burn”, Zelensky said in his message, describing its bombardment of Kharkiv with S-300 missiles and guided aerial bombs.

Ukraine’s air force said that overnight into Sunday Russia launched another 14 missiles and more than 30 attack drones on Ukraine.

It said it downed all but two of the missiles.

In the central Vinnytsia region, fragments from a downed drone wounded three people and damaged houses and blocks of flats, regional authorities said.

On Saturday evening, another strike hit the centre of Kharkiv city, wounding 25 in an area containing multi-storey buildings and a research institute, Synegubov said.

Kharkiv, Ukraine’s second-largest city, is just a few dozen kilometres from the border and regularly comes under attack from Russian missiles.

The latest attacks came after Russia launched a ground offensive in the Kharkiv region on May 10.

Ukraine said on Friday that it had managed to halt Moscow’s progress and was counter-attacking.

Russia on Sunday claimed the capture of the village of Berestove in the Kharkiv region, located on the eastern front line close to the Luhansk region.

“France shares the pain of the Ukrainians and remains fully mobilised alongside them,” he said.

Zelensky had visited Kharkiv on Friday and met officials to discuss the defence of the surrounding region.

On Saturday, he urged world leaders to supply Ukraine with “sufficient air defence protection” to “prevent such terrorist attacks”.

Russia and Ukraine accused each other’s forces of attacks along the border on Saturday.

Russia said Ukraine shelled a small town in the Belgorod region, killing two people and wounding 10.

Ukraine said Russia shelled the village of Kupiansk-Vuzlovyi, a railway hub in the region of Kharkiv, wounding five, the regional prosecutor’s office said.

It said two vehicles came under fire: a car with two passengers and an ambulance with a driver, a paramedic and a 64-year-old patient.

Russia also carried out air strikes on the Kupiansk district, damaging a factory and residential buildings, prosecutors said.

In the eastern Donetsk region, shelling on Saturday killed a 40-year-old woman and wounded four other people, said the head of the regional administration, Vadym Filashkin.