Three hundred families of Islamic State group fighters have fled the jihadists' self-proclaimed Syrian capital of Raqqa in 24 hours, as rival forces advance on the city, a monitor said Saturday.
The Syrian Observatory for Human Rights said "300 families of foreign fighters of IS have left the city of Raqqa since dawn Friday to take refuge in the province of Deir Ezzor to the east and Hama to the west".
The northern city of Raqqa is the target of advancing Turkish-backed Syrian rebels, a US-backed alliance of Kurdish and Arab forces as well as Syrian government troops supported by Russia.
The Observatory's head, Rami Abdel Rahman, said that IS families were using the only remaining escape route, on boats across the Euphrates River to the south.
The United States on Thursday turned up the heat on the jihadists, sending an additional 400 American troops into Syria to support operations to retake Raqqa.