BAGHOUZ, Syria (REUTERS) - Islamic State in Iraq and Syria (ISIS) faced imminent defeat in its final enclave on Tuesday (March 12) as hundreds of militant fighters and their families surrendered and the US-backed Syrian Democratic Forces said the battle was as good as over.

A Reuters journalist in Baghouz saw hundreds of people surrendering to the SDF, which launched its final attack to capture Baghouz on Sunday, backed by US-led international coalition air strikes and after weeks of siege.

The enclave is the last shred of territory held by the extremists who have been driven from roughly one third of Iraq and Syria over the past four years.

SDF official Mustafa Bali said that 1,500 to 2,000 ISIS fighters and their families surrendered en masse on Tuesday.

“Once our forces confirm that everyone who wants to surrender has done so ... the clashes will resume,” he said. The militants’ defeat was very near, he said.

The coalition said in an email earlier on Tuesday there were an estimated “few hundred” foreign ISIS fighters remaining in Baghouz who had decided to fight to the end.

The Baghouz enclave was pounded overnight with barrages of rockets, and fires raged inside, but the situation was calm on Tuesday morning.

“The operation is over, or as good as over, but requires a little more time to be completed practically on the ground,” SDF spokesman Kino Gabriel told al-Hadath TV.

The SDF has laid siege to Baghouz for weeks but has repeatedly postponed its final assault to allow thousands of civilians, many of them wives and children of ISIS fighters, to leave. It resumed the attack on Sunday.

Gabriel said 25 ISIS fighters had been confirmed killed so far in clashes, in addition to an unknown number of militants killed by air strikes. Another SDF official said earlier 38 militants had been confirmed killed.

The SDF, which is spearheaded by the Kurdish YPG militia, has been advancing slowly into Baghouz to minimise its losses from sniper fire and landmines.

Three SDF fighters have been killed, Bali said on Twitter.

TUNNELS

ISIS' defences include extensive tunnels. The militant group’s most hardened foreign fighters are holed up inside the enclave, the SDF has said.

However the United States does not believe any senior ISIS leaders are in Baghouz, assessing they have gone elsewhere as part of the group’s shift towards guerrilla tactics, a US defence official has said.

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Fighters surrendering from Baghouz are questioned and searched.

While Baghouz is the last populated territory of what was once the group’s self-proclaimed “caliphate”, fighters still operate in remote areas elsewhere. It is widely assessed that they will continue to represent a potent security threat.

Even as the last shred of its physical statelet crumbled, the group put out a new propaganda video, filmed in recent weeks inside Baghouz, insisting on its claim to leadership of all Muslims and calling on its supporters to keep the faith.

“Tomorrow, God willing, we will be in paradise and they will be burning in hell,” it showed an ISIS member identified as Abu Abd al-Azeem saying.

Most of the people evacuated from the diminishing ISIS territory have been transported to a camp for internally displaced people in al-Hol, in northeastern Syria, where the United Nations says conditions are dire.

The camp, designed to accommodate 20,000 people, is now sheltering more than 66,000.

The World Health Organisation said on Tuesday 106 people, mainly infants, have died since December on the journey to al-Hol, which takes at least six hours.

Many evacuees, particularly foreigners, still express obdurate support for ISIS, posing difficult security, legal and moral questions for their countries of origin.

Those issues were underscored on Friday with the death of the newborn son of Shamima Begum, a British woman who left London to join ISIS when she was a schoolgirl. Britain stripped her of her citizenship on security grounds last month.