Scores of ISIS fighters surrendered to US-backed forces in Syria Monday, following a weeks-long siege of a small border town near Iraq, a war monitor reported.

Roughly 150 jihadists — and 250 civilians — emerged from their enclave in the eastern town of Baghouz, according to the UK-based Syrian Observatory for Human Rights.

US-backed Syrian Democratic Forces had chased fighters down the Euphrates River to Baghouz, one of ISIS’s last-standing holdouts along Syria’s border with Iraq.

Firefights erupted on the town’s outskirts over the weekend, but the SDF announced Monday it would ease pressure on the town after learning civilians remained inside.

“We’re slowing down the offensive in Baghouz due to a small number of civilians held as human shields by Daesh,” SDF spokesman Mustafa Bali said on Twitter, using the Arabic acronym Daesh for Islamic State.

The SDF did not immediately confirm the surrender — or say how many ISIS fighters are believed to remain in Baghouz — but Bali has vowed “the battle to retake the last ISIS holdout is going to be over soon.”

Reclaiming Baghouz would mark a major defeat for ISIS, but observers warn that terror sleeper cells could remain in remote areas.

With Post wires