52 pro-regime fighters killed

An air strike has killed more than 50 pro-regime fighters in eastern Syria, most of them foreign, with the US-led coalition denying accusations from Damascus it was behind the attack.

The strike just before midnight hit Al-Hari, a town controlled by regional militias fighting in the complex seven-year war on behalf of President Bashar al-Assad.

The Syrian Observatory for Human Rights, a Britain-based monitor of the conflict, said 52 pro-regime forces were killed in one of the deadliest air attacks in recent months.

"Among them are at least 30 Iraqi fighters and 16 Syrians, including soldiers and members of loyalist militias," Observatory chief Rami Abdel Rahman told AFP.

The nationalities of the remaining six fighters were not immediately known, he said. There are Iraqi, Iranian, Lebanese and even Afghan fighters stationed in the area.

According to Abdel Rahman, some wounded fighters were treated in the nearby town of Albu Kamal while others travelled across the border to Iraq.

A military source in Deir Ezzor told AFP the warplanes hit "joint Iraqi-Syrian positions in Al-Hari".

The attack was first reported by Syrian state media overnight, which cited a military source and accused the US-led coalition fighting the Islamic State group of carrying it out.

It said several people were killed and wounded but did not give a specific number or their nationalities.

The coalition's press office said it had heard reports that a strike in the area had killed and wounded members of a pro-regime Iraqi militia, but denied it was responsible.