BEIRUT: US-backed militias said they came under attack on Saturday from Russian jets and Syrian government forces in Syria’s Deir Al Zor border province, a focus of an increasingly complex conflict.

The strikes wounded six fighters from the Syrian Democratic Forces (SDF), according to the alliance of mostly Kurdish and Arab militias fighting alongside a US-led military coalition.

The United States and Russia are backing separate offensives in Syria’s multi-sided conflict — with both sides advancing against Daesh in the eastern region that borders Iraq.

The separate assaults by the Russian-supported Syrian government and the US-supported SDF have raised fears that clashes that could stoke tensions between the competing world powers.

“Our forces east of the Euphrates were hit with an attack from the Russian aircraft and Syrian regime forces, targeting our units in the industrial zone,” the SDF said in a statement.

Such attacks “waste energies that should be used against terrorism, threaten the security of the region, and open the door to side conflicts,” it said.

There was no immediate comment from the Syrian government or from Moscow.

Both offensives are converging on Daesh from opposite sides of the Euphrates river — the Syrian army with allied forces from the west and the SDF from the east.

The Russian- and US-backed offensives against Daesh in Syria have mostly stayed out of each other’s way as the two states seek to avoid conflict, with the Euphrates often acting as a dividing line between them.

On Friday, Ahmad Abu Khawla, who heads the SDF’s Deir Al Zor military council, said his forces would not let government forces cross.

A senior aide to Syrian President Bashar Al Assad said the government would fight any force, including the US-backed militias, in efforts to recapture the entire country.

Daesh is also coming under attack by US-backed Iraqi government forces just over the border from Syria’s Deir Al Zor inside Iraq.

Daesh’s declaration in 2014 of a self-proclaimed “caliphate” spanning both countries effectively collapsed in July, when an Iraqi offensive captured Mosul, the terrorists’ capital in Iraq.