All IS fighters have fled former caliphate stronghold Raqqa: human rights monitor

All Syrian fighters of the Islamic State group have left the jihadists' one-time bastion of Raqqa and preparations are under way for foreign combatants to leave, a monitor said on Saturday.

The jihadists left Raqqa with their families, heading to unknown destinations, the Britain-based Syrian Observatory for Human Rights said.

"All Syrian fighters from the Islamic State group left Raqqa over the past five days," Observatory head Rami Abdel RahThe US-led coalition told AFP on Saturday dozens of fighters from the Islamic State group have surrendered over the past day in Raqqa. 

"Within the past 24 hours, approximately 100 ISIS terrorists have surrendered in Raqa, and were removed from the city," the coalition said in an emailed statement.

But it added "foreign fighters (were) not being allowed to leave".

A Raqqa official told AFP on Saturday Syrian IS members had surrendered overnight to the US-backed Syrian Democratic Forces battling to take full control of the city, without specifying how many.

"Those that surrendered are local, not foreigners - the foreigners have not handed themselves in yet," the official said.

"They sent a message to the Raqqa Civil Council and to the tribal mediators."

Members of the RCC - a provisional administration for the city set up by the SDF - had been working with tribal leaders throughout the week to try to secure safe passage for civilians. 

Hundreds of civilians have managed to flee the battle-ravaged city, which once served as the de facto Syrian capital of the jihadist group. 

According to Mr Abdel Rahman, up to 150 foreign jihadists remain in the city and negotiations on their fate are still ongoing.

"The foreign fighters are asking to leave in one group towards areas under IS control in Deir Ezzor province" in eastern Syria, he said. 

But a spokesman for the Kurdish People's Protection Units (YPG), which spearhead the SDF, denied on Saturday any discussions were taking place for the surrender of the city.

"We completely deny any negotiations or deal for the exit of Daesh. Until this very moment, we are fighting Daesh," Nuri Mahmoud told AFP.

Backed by US-led coalition air strikes, the SDF's Arab and Kurdish fighters have recaptured around 90 per cent of Raqa from IS. man said, adding they numbered about 200 fighters.