Zelensky initially put the death toll at 18, but Ukraine's state emergencies service DSNS later said 24 people, including two rescuers and four police officers, were confirmed to have been killed.

In his video address late on Monday, Zelensky said 26 people were now known to have died.

He earlier said that "the Russians could not have been unaware that the local residents who remained in Komyshuvakha received humanitarian aid there every week" on Monday.

"This is yet another proof that Russia does not want any de-escalation."

He said that after a recent successful joint Russian-Ukrainian operation to evacuate civilians from the Russia-occupied southern city of Oleshky during a temporary ceasefire brokered by US First Lady Melania Trump,"there was a moment when the next steps could show that peace is possible".

"With such killings, Russia is sending the exact opposite signal - Russia is counting on further killings," Zelensky said.