Islamic State (Isis) has abducted around 2,000 civilians in northern Syria, according to US-backed forces and a monitoring group.

The alliance of Arab and Kurdish groups, the Syrian Democratic Forces (SDF), said that Isis (Daesh) militants fleeing the city of Manbij had seized the civilians.

"While withdrawing from a district of Manbij, jihadists abducted around 2,000 civilians," the SDF said, reported AFP. This was subsequently confirmed by monitoring group the Syrian Observatory for Human Rights (SOHR).

Earlier on Friday (12 August), the SDF said that it had begun its final assault to seize control of the Isis-controlled city, which is strategically located near the Turkish border.

Friday's attack is "the last operation and the last assault," Sharfan Darwish, an SDF spokesman, told Reuters.

He added that around 100 Isis militants were still holed up in the city centre where they were using civilians as human shields. The SOHR said about 500 Isis militants and civilians loyal to the group had fled the town in cars and other vehicles and were heading towards the Daesh-controlled town of Jarablus.

The SDF, supported by US airstrikes, began the campaign to seize Manbij in May, but faced heavy resistance from Isis fighters when it reached the centre of the city.