US-backed forces captured the last major town held by ISIS in eastern Syria on Wednesday, and are now sweeping surrounding villages for remnants of the militant group, activists said.
The Syrian Democratic Forces, a coalition of Arab and Kurdish fighters, have seized several eastern villages from ISIS, including Hajin, Al Shaafa and Sousa, in recent weeks.
On Wednesday, they captured Al Baghouz, the last major town under militant control, the UK-based Syrian Observatory for Human Rights said.
The Observatory said search operations are ongoing to find any ISIS fighters who may have gone into hiding in the town. It also said that the SDF are working to clear militants from farmlands around Al Baghouz.
The war monitor said that ISIS defences in Al Baghouz "collapsed" after hundreds of militants fled the area over the past two days. The Observatory said nearly 500 ISIS fighters and thousands of their relatives have fled the group's last bastion since Monday.
This raises the total number of people who have escaped ISIS territory since December to over 27,000, according to the war monitor.
The SDF posted pictures on social media networks on Wednesday purporting to show those who have fled ISIS territory, including the relatives of militants. It said they included nationals from France, Pakistan, Iraq and Turkey.
The activist-run DeirEzzor24 news website also said that the SDF had advanced in Al Baghouz after fierce clashes with militants. It posted a video on social media networks purporting to show fighters entering Al Baghouz.
"The SDF and the International Coalition are close to ending Daesh completely east of the Euphrates," it said.
DeirEzzor24 head Omar Abu Layla told The National that a small number of militants remain in areas surrounding Al Baghouz.
They are holed up in farmlands on the outskirts of the village.
He said he expected the SDF would remove them "within hours", but that this would not spell the total defeat of the militants.
"There are many ISIS cells that are still active and that are carrying out attacks, arrests and assassinations," he said. "An announcement of an ISIS defeat would only be superficial."
The US-led coalition declined to say when it expected its SDF allies to overrun the final sliver of territory still under militant control.
It stressed the operation's bigger goal was to minimise the continuing threat ISIS could pose from underground.
"It is difficult to say how much longer, despite the progress," coalition spokesman Colonel Sean Ryan said.
"We try to stay away from timelines as it is more about degrading the enemy's capabilities."
Kurdish-led forces, backed by airstrikes of the US-led coalition, have been battling since September to expel militants from their enclave in the eastern province of Deir Ezzor.
The battles have killed more than 1,000 ISIS militants and more than 600 SDF fighters.
It has also displaced thousands of civilians, many of whom are now languishing in informal settlements in Kurdish-held parts of eastern Syria.
Battles against ISIS in eastern Syria gained pace after US President Donald Trump last month announced he would withdraw US forces from the country.
The coalition also stepped up airstrikes against militants, after ISIS targeted American personnel in the northern Syrian city of Manbij last week.
The suicide bombing killed four American personnel and 15 other people. The US losses were the biggest since Washington entered the conflict in 2014.
On Monday, ISIS targeted a US army convoy in the town of Al Shadadeh in northeast Syria. The US-led coalition said that no American troops were killed in the car bombing.