The US-backed Syrian Democratic Forces said it thwarted an attempted ISIS group suicide bomb attack early on Wednesday during a last-stand battle for the militant group’s final enclave. The SDF on Tuesday said the battle for Baghouz, a collection of hamlets and farmland near the Iraqi border, was as good as over. The enclave is the last shred of populated territory held by the militants who have been driven from roughly one third of Iraq and Syria over the past four years. Mustafa Bali, a spokesman for the SDF media office, said its forces had been bombarding Baghouz heavily overnight before engaging in direct clashes with ISIS militants from 4-6 am (0200-0400 GMT). “There were suicide vest attacks by a group of bombers who tried to blow themselves up amidst our forces. Our forces targeted and killed them before they reached our positions,” Bali said. The SDF has laid siege to Baghouz for weeks but had repeatedly postponed its final assault to allow thousands of civilians, many of them wives and children of ISIS militants, to leave. It resumed the attack on Sunday. Around 3,000 fighters and their families surrendered to SDF forces in 24 hours, Bali said overnight. Three women and four children belonging to the Yazidi sect, a minority group who were kidnapped and enslaved by ISIS in 2014, were also freed, he said. A ragged tent encampment in the eastern Syrian village of Baghouz is all that remains of a once-sprawling ISIS groups "caliphate" declared in 2014 across large swathes of Syria and neighboring Iraq. While Baghouz is the last populated territory for ISIS, militants still operate in remote areas elsewhere. The group put out a new propaganda video overnight Monday filmed in recent weeks inside Baghouz, insisting on its claim to leadership of all Muslims and calling on its supporters to keep the faith. The militants have continued to claim deadly attacks in SDF-held territory in recent months, and the US military has warned of the need to maintain a "vigilant offensive". "If we had thousands of kilometers and now we only have some kilometers left, it is said we have lost -- but Gods judging standard is different," said a man named Abu Abdel Adheem in the video. "The battles are not over," he said, sitting on the ground in a circle with two men and a young boy in a hooded jacket. Baghouz is the latest front on Syrias complex civil war, which has killed more than 360,000 people since 2011.