IS 'on the ropes' in northern Syria, says US

Following the recapture of Manbij by US-backed forces, the Islamic State group militants have been put "on the ropes" in northern Syria, a Pentagon official said.

Syrian Democratic Forces - a coalition of Kurdish and Arab fighters - began an operation to capture Manbij on 21 May, and have since then wrested control of more than 1,000 square kilometers (386 square miles) of territory from IS.

Manbij is a key town in the anti-IS struggle because the militants were using it as a waypoint between the Turkish border and Raqqa, the group's de facto "capital".

Arab-Kurdish forces - backed by US-led coalition air power - have now forced IS to retreat from Manbij in a long campaign to capture the city.

"Although fighting in Manbij continues, [IS] is clearly on the ropes. It has lost the center of Manbij, it has lost control of Manbij," Pentagon deputy press secretary Gordon Trowbridge said.

IS fighters fled the city on Friday, seizing around 2,000 civilians to use as "human shields", the SDF and the Syrian Observatory for Human Rights monitoring group said.

Hundreds of them were released on Saturday.

Trowbridge said US officials were aware of the reports but unable to confirm them.

"[IS] has consistently shown a willingness to put innocent lives at risk, in blatant violation not only of the laws of armed conflict but of common human decency," he said.

Since fighting for Manbij began, US-led strikes have taken out more than 50 of IS' heavy weapons and destroyed more than 600 fortified fighting positions, Trowbridge said.

But the job of clearing the city will be complicated after the militants left behind hundreds of mines and booby traps, he added.