Separate airstrikes by Russian forces and the United States-led coalition killed 35 civilians in Syria’s eastern Deir Ezzor province on Tuesday, a human rights monitor said.

The Deir Ezzor province, which lies along Syria’s border with Iraq, is seen as a strategic prize by both the Russian-backed Syrian regime and an alliance of Kurdish and Arab forces supported by the US-led coalition, reported AFP. The US and Russia are conducting parallel offensives against the Islamic State group in the region.

The Syrian Observatory for Human Rights, a Britain-based monitor, had earlier reported that 28 people had died in the Russian and US-led strikes. Russian airstrikes on the western bank of the Euphrates river killed “16 civilians, including five children”. The US-led raid in the village of Al-Shahabat killed 12 of a family, including five children.

The observatory later raised the toll, after new Russian raids on Hawayej Thiab village in the west of the province.