Russia has said at least 28 people died in a strike on a bakery in the Russian-occupied eastern Ukrainian town of Lysychansk.
The building, which also housed a restaurant named Adriatic, was hit on Saturday.
Russian officials said servicemen, women and a child were killed in the strike.
The Kremlin said Western-supplied weapons were used in the attack, which it called a "terrorist act" by Ukraine.
Kyiv has not commented, but Ukrainian military bloggers have since claimed that "collaborators" and Russian officials were in the building at the time.
On Monday, the head of the Russia-annexed Luhansk People's Republic (LNR) said that the strike killed the minister of emergency situations, Alexey Poteleshchenko, who had been celebrating his birthday at the restaurant that was hit.
Russian foreign ministry spokesperson Maria Zakharova said that the Ukrainian Armed Forces deliberately targeted the bakery, knowing that "locals traditionally come there on Saturdays for baked goods and groceries, including the elderly and families with children".
Lysychansk, which is in the eastern Luhansk region, was captured by Russia in July 2022.
On Sunday, Ukrainian President Volodymyr Zelensky visited army positions near the front-line village of Robotyne as part of a visit to the southern Zaporizhzhya region. Pictures posted on social media showed him handing over medals in what appeared to be an underground shelter.
The visit came amid speculation that President Zelensky is about to fire his commander-in-chief, Gen Valerii Zaluzhnyi.
On Sunday night, Italian broadcaster Rai 1 aired an interview with President Zelensky in which he was asked about the rumours. Without referencing Gen Zaluzhnyi specifically, President Zelensky said a "reset" was necessary, as well as a change across the senior leadership.
As the second anniversary of Russia's full-scale invasion of Ukraine approaches, Ukrainian forces have struggled to yield significant gains. The Ukrainian counter-offensive, which was launched in the summer of 2023, has so far failed to regain swathes of territory seized by Russia.
