President Volodymyr Zelensky said Moscow bombed a boarding school in Russia occupied by the Ukrainian where civilians were sheltering and preparing to evacuate.
The Ukrainian army said that four people had been killed and that dozens – many of whom were injured – were injured in the city of Sudzha in the Kursk region, which has been under Ukrainian control for five months.
More than 80 people have been saved from the building.
The BBC was unable to confirm the assertion of Ukraine that it was a deliberate Russian attack using a guided air bomb. Moscow blamed Ukraine for bombing.
Zelensky posted on X that the incident exposed Russia as “a state without civility”.
“This is how Russia made war-Sudzha, Kursk region, Russian territory, a boarding school with civilians preparing to evacuate,” he wrote.
“A Russian aerial bomb. They destroyed the building even if dozens of civilians were there.”
The Ukrainian army staff posted on Telegram that four people had died and that 84 civilians had been rescued, adding that “the strike was made on purpose”.
For its part, the Russian Ministry of Defense said that Ukraine had led the attack on Saturday, which it described as a targeted missile strike.
Ukraine launched a thunderbolt in the Russian Oblast of Kursk last August, taking Russian border guards by surprise.
The government of Kyiv clearly indicated at the time that it did not intend to keep the territory seized, simply to use it as a bargaining currency in future peace negotiations.
Zelensky compared the strike on Saturday to “how Russia waged war in Chechnya decades ago. They killed Syrians in the same way. Russian bombs destroy Ukrainian houses in the same way”.