The terrorists punched back into the town they had lost a day earlier and swiftly retook several northern neighborhoods, the Syrian Observatory for Human Rights monitor said.
“IS (Daesh) started counterattacking on Thursday night and retook more than 40 percent of the town of Albu Kamal,” Rami Abdul Rahman, head of the Britain-based Observatory, told AFP.
Albu Kamal was the last significant town to have been under full Daesh control and lies at the heart of what used to be the sprawling “caliphate” the group declared in 2014 over swathes of Iraq and Syria.
“The terrorists went back in and retook several neighborhoods in the north, northeast and northwest,” Abdel Rahman said. “IS is trying to defend its last bastion.”
The terror group has in the space of a few weeks seen its caliphate shrink to a small rump and lost major cities such as Mosul, Raqqa and Deir Ezzor.
The observatory said most of the fighting was done by the Lebanese Shiite group Hezbollah and elite forces from its backer Tehran, as well as militia groups from Iraq.
Losing the town, where IS leaders used to meet and were once considered untouchable, would cap a process which has seen the group relinquish any ambition as a land-holding force and return to the desert to fight a clandestine guerrilla war.
Many of the group’s top leaders have been killed as Syrian and Iraqi forces with backing from Russia, Iran and a US-led coalition rolled back the territorial losses that saw the terrorists declare a “caliphate” roughly the size of Britain in 2014.
But the whereabouts of the first among them, self-proclaimed “caliph” Abu Bakr Al-Baghdadi, remains unclear. He has been reported killed or wounded many times but Daesh has never offered any confirmation.
In Deir Ezzor province, which used to be the heartland of their proto-state, the group’s remaining fighters only control about 30 percent of territory, most of it desert.
On the other bank of the Euphrates, coming from the north, the Kurdish-led US-backed forces that retook the Daesh “capital” of Raqqa last month were also advancing on Daesh positions.
According to the observatory, the Syrian Democratic Forces (SDF) retook four villages from Daesh there on Friday.
Observers have predicted the regime may seek to retake towns and cities wrested from Daesh by the SDF, such as Raqqa which the terrorists had used as their main Syrian hub.