US-backed forces push into last ISIS toehold in Syria as death toll is said to rise into hundreds

US-backed forces in Syria have pushed deep into the country’s last major ISIS holdout, where high-value militant targets are believed to be present.

The Syrian Democratic Forces entered the centre of Hajin, the main town in an ISIS-held pocket on the eastern banks of the Euphrates, SDF spokesman Mustafa Bali said on Twitter.

A video posted by the SDF official showed fighters walking in the town, where damage was extensive. Gunfire was heard in the background. The National could not independently verify the authenticity of the video.

The UK-based Syrian Observatory for Human Rights said Kurdish-led force “destroyed ISIS defences” in Hajin and captured wide areas from militants in the past 48 hours.

The war monitor said militants were confined to Hajin’s eastern flanks and tunnels built inside the town. About 7,000 civilians are believed to be trapped in the town, according to the UN.

ISIS has been pushed from almost all the territory it ruled in Iraq and Syria, but the militant group has managed to retain a toehold near the Iraqi border for more than a year. The pocket around Hajin is about 50 square kilometres, believed to be home to high-profile ISIS militants who fled former ISIS territories.

Mr Bali on Wednesday said ISIS was “still strong” in Hajin and that hundreds of foreign fighters were based in the town.

In September, the SDF, which now controls much of eastern Syria, announced a final push against militants in Hajin, but deadly ISIS counter-attacks stymied progress.

The Kurdish-led alliance temporarily suspended operations in October because of Turkish threats to Kurdish heartlands farther north.

Europe-based Omar Abu Layla, of activist-run monitoring group DeirEzzor24, confirmed the market was taken, as well as the main mosque in Hajin. “The end of the [ISIS] organisation in Hajin is very near,” he said.

Col Sean Ryan, a spokesman for the US-led coalition against ISIS, said “the SDF has progressed into [Hajin], and the advancement is going well”, but it was too early to say that the entire city had been captured.

No casualty toll was available, but according to the Observatory, about 500 SDF fighters have been killed since the start of the operation on September 10.

About 300 civilians have been killed, many of them in coalition air strikes, and thousands have been forced to flee their homes.

YPG spokesman Nuri Mehmud said threats by Turkey to launch a new military operation against US-backed Kurdish fighters in Syria will negatively affect their fight against ISIS.