BAGHOUZ, Syria — Around 3,000 Islamic State members have surrendered from the group’s last holdout in Syria, Kurdish-led forces said on Tuesday, as air raids and shelling resumed after a brief lull.

A ragged tent encampment in the eastern Syrian village of Baghouz is all that remains of a once-sprawling IS group’s "caliphate" declared in 2014 across large swathes of Syria and neighbouring Iraq.

The US-backed Syrian Democratic Forces (SDF) has been trying to crush holdout IS fighters for weeks but the mass outpouring of men, women and children from the riverside hamlet has bogged down its advance.

Backed by the US-led coalition, the SDF renewed its assault Sunday after warning remaining IS fighters their time was up.

Air strikes and shelling have since pummelled Baghouz three nights in a row, killing scores of fighters and prompting hundreds of jihadists and their relatives to surrender.

Thousands handed themselves over Tuesday, after a deluge of fire hit the IS encampment the previous night.

"Number of Daesh (IS) members surrendered to us since yesterday evening has risen to 3,000," Syrian Democratic Forces spokesman Mustefa Bali tweeted in English on Tuesday evening.

Three women and four children of the Yazidi minority were also rescued, he added.

The SDF and the US-led coalition resumed shelling and air strikes on the last IS bastion Tuesday evening, interrupting a brief lull in fighting that had taken hold during the day to allow for people to surrender.

An AFP correspondent near the front line heard warplanes rumbling overhead, as the sound of mortar fire and explosions rang from the IS encampment.

Dozens of SDF fighters massed at the entrance of the village of Baghouz on Tuesday evening.

Sherif, the unit commander, said his force was preparing to storm the jihadist redoubt.

"We readied ourselves today and our spirits are high," he said.

"We will enter with full force and we will be at the forefront" of the advance, said the fighter who has been battling jihadists for years.

’Terrorising IS fighters’

Earlier on Tuesday, Ali Cheir, an SDF unit commander, said his force and the coalition were pummelling the IS enclave at night to flush out jihadists.

"The objective of our advance is to terrorise IS fighters so they surrender, and for the civilians to come out," said the 27-year-old.

Coalition warplanes Monday pounded the jihadist redoubt with 20 air strikes, destroying armoured vehicles and arms caches, SDF spokesman Mustefa Bali said.

He said US-backed forces clashed with jihadists on several fronts, killing nearly 40 IS fighters.

Since December, around 60,000 people have left the last IS redoubt, according to the Britain-based Syrian Observatory for Human Rights, around a tenth of them suspected jihadist fighters.

The United Nations said the numbers from Baghouz arriving in one Kurdish-run camp further north for the displaced were smaller than in previous weeks.

It said they were reaching the camp in a worse state than before.

The UN’s food agency said it is concerned about their wellbeing.

"On Sunday night more than 3,000 people, mostly women and children in a poor state, reached the camp," the WFP said.

"WFP is deeply concerned about the welfare of tens of thousands of people recently arriving at the Al-Hol camp," it said on Tuesday.

Around 113 people -- two-thirds of them children under five -- have died en route to the camp or shortly after arriving since December, the UN’s humanitarian coordination office OCHA says. — AFP