Between 300 and 400 Daesh group terrorists remain in their one-time Syrian bastion of Raqqa where Syrian Democratic Forces (SDF), dominated by the PKK terrorist group, are fighting to seize full control, its U.S.-led coalition backer said Thursday.

"We are looking at approximately 4,000 civilians who remain in Raqqa, and a matter of 300-400 remaining [Daesh] fighters," coalition spokesman U.S. Colonel Ryan S. Dillon told a news conference in Baghdad.

Officials from Raqa Civil Council – a provisional administration set up by the SDF – are trying to negotiate the safe passage of civilians from remaining Daesh-held areas.

"We have seen a trend of [Daesh] surrendering over these last months, about four to five per week ... including emirs and leaders," said Dillon, adding that others were captured trying to blend in with departing civilians.

U.S.-backed SDF is predominantly led by the terrorist PKK's Syrian affiliate the People's Protection Units (YPG).