On Friday, the Takfiri militants used at least 10 suicide bombers in their offensive on Albukamal, quickly overrunning several of its neighborhoods, the so-called Syrian Observatory for Human Rights said.
It was the biggest attack on the town in the eastern province of Deir ez-Zor since the terror group lost it to Syrian forces in November 2017, the Britain-based monitor said.
On Monday, "(Syrian) forces and their allies regained control of the whole town of Albukamal after expelling Daesh from its northern and northwestern parts," Observatory head Rami Abdel-Rahman said, according to AFP.
The militants fled back into Syria's vast Badiya desert, which stretches from the country's center to the border with Iraq, he said.
Daesh lost its so-called "caliphate" it declared in 2014 in Syria and neighboring Iraq, but still holds slithers of land in the desert and east of the country.