Air strikes by unidentified warplanes have killed five pro-Iran fighters in Syria's eastern province of Deir Ezzor near the Iraqi border, a Britain-based war monitor said on Sunday. The strikes late Saturday targeted "positions of Iranian forces and allied militias" on the edge of the town of Albukamal, the Syrian Observatory for Human Rights said.

"Five non-Syrian fighters were killed," Observatory chief Rami Abdel Rahman told AFP, without being able to provide their nationalities. Regime troops, Iranian forces and allied Iran-backed fighters, including from Iraq, are present in the area on the western banks of the Euphrates River, he said.

A US-led coalition has been backing Kurdish-led forces fighting Islamic State group fighters on the eastern shores of the river. The coalition has in the past admitted to carrying out air strikes against pro-regime fighters, but it denied any involvement in Saturday's air raids.

Copyright Agence France-Presse, 2019