The US-backed Syrian Democratic Forces militia on Monday accused Russia of killing one of its fighters and wounding others at a gas facility it captured two days ago from the Islamic State group in eastern Syria.

"Russian air strikes and mortar fire hit the Conoco gas plant where a large number of our forces are stationed," SDF spokeswoman Lilwa Abdallah told AFP.

A statement issued later by the militia said one fighter had been killed and six more injured in the bombing.

Abdallah said Syrian regime forces carried out additional bombardment of SDF positions after the initial Russian bombing.

"We reserve the right to respond," she added.

The SDF, an alliance of Kurdish and Arab fighters, captured the Conoco plant in Syria's Deir Ezzor province on Saturday.

The militia is fighting a campaign against IS on the eastern side of the Euphrates river that cuts diagonally across Deir Ezzor, a resource-rich province that borders Iraq.

Syria's regime, backed by its ally Russia, is carrying out its own campaign against IS in Deir Ezzor, largely on the western side of the Euphrates, including in the provincial capital Deir Ezzor city.

A "de-confliction" line is supposed to prevent the two campaigns from clashing, but Monday's alleged bombardment is the second time the SDF has accused Russia and the regime of hitting its fighters.

On September 16, the group said six of its fighters were wounded in air strikes by regime and Russian warplanes in the Al-Sinaaiya area around seven kilometres (four miles) from the eastern bank of the Euphrates.

And on September 21, Moscow warned Washington of reprisals after accusing the SDF of firing on Syrian regime forces in the province.

Source: AFP