Syria’s army and its allies have encircled Daesh (IS) in the city of al-Mayadin, southeast of Deir al-Zor, in eastern Syria, a Syrian military source said on Sunday.
Al-Mayadin is one of the last strongholds of Daesh as it falls back upon the fertile area downstream of Deir al-Zor in the Euphrates valley and launches counter attacks in the central desert after losing swathes of territory this year.
The army and its allies reached Deir al-Zor in September after a months-long offensive across the Syria desert, and have in recent weeks pushed down the Euphrates towards al-Mayadin.
However, counter attacks by Daesh in the central desert region have put pressure on the main supply road to Deir al-Zor from western Syria.
A U.S.-led coalition is also supporting a rival campaign against the jihad Daeshts, mostly on the east bank, where it is close to recapturing Raqqa, and has also advanced downstream to hold areas opposite Deir al-Zor.
U.S. officials have previously said that Daesh had relocated some of its diminished command and propaganda structures to al-Mayadin as it was forced from territory elsewhere.