At least 53 civilians, including 22 children, were killed allegedly after Russian airstrikes early on Sunday hit residential buildings in a village held by the Islamic State group in East Syria, AFP reported.

The Britain-based Syrian Observatory for Human Rights initially pegged the toll at 34 civilians, but the figure rose after more bodies were recovered through the day. The monitor, which receives information from a network of sources inside Syria, said the air raids hit the village of Al-Shafah in the Deir Ezzor province.

“The toll increased after clearing debris in a long day of rescue operations,” Rami Abdel Rahman, the head of the Syrian Observatory for Human Rights, told AFP. At least 18 people were injured.

Syria’s Deir Ezzor is one of the last places under the control of the Islamic State group. The terror outfit has been driven out of its major strongholds in a series of raids this year by Russia, Syria and United States-backed forces.

Russia, an ally of Syria’s President Bashar al-Assad, began a military intervention in September 2015 to help the Syrian government regain territory from the Islamic State. Sunday’s strike in Deir Ezzor come as the United Nations tries to end the six-year civil war that has killed more than 3.4 lakh people and left huge swathes of Syrians as refugees.

On Tuesday, the eighth round of UN-brokered talks will begin.