IS pushes back against US-backed forces in Syria's Raqqa

Islamic State militants fought on Friday to repel the advance of U.S.-backed Syrian forces, days after they inched closer to the heart of the extremist group's de facto capital of Raqqa.

The Britain-based Syrian Observatory for Human Rights said the IS fighters were waging counterattacks in the Old City of Raqqa, where the U.S.-backed Syrian Democratic Forces have advanced some 200 meters (yards) beyond the city's outer walls.

Days earlier, the Kurdish-led SDF, backed by airstrikes from the U.S.-led coalition, had punched two gaping holes in the 2,500 meter (yard) long wall to take the fight to the city center. Activists said the advancing forces now control most of the Old City wall, dating back 1,300 years.

The Kurdish-run Hawar news agency said the SDF clashed with the militants in the city's Rawda district, northeast of the Old City walls. The agency said the Kurdish-led forces were now within firing range of the city's grain silos, further to the north.

Hawar interviewed residents of the Old City who had managed to escape from the IS-held city. They said that over the past weeks, they had no water and one man said a bottle had to last them a week, according to the video.

The U.N. estimates there are between 50,000 to 100,000 civilians trapped with IS militants inside Raqqa.

There are also clashes with IS militants south and west of Raqqa city, the Observatory reported.

The campaign to seize Raqqa began in earnest on June 6, with a multi-pronged assault by the Kurdish-led SDF. Last week, the U.S.-backed fighters crossed the Euphrates River on the southern edge of the city, completing its encirclement.