For weeks, reports have circulated of serious clashes between insurgents and the Islamic State of Iraq and as-Sham in Deir Ez Zor Province in northeastern Syria.

Expelled from many of its positions except for the city of Raqqa in northern Syria, IISIS appears to be concentrating forces on the fight for Deir Ez Zor and Hasakah Provinces, home to Syria’s oilfields. Unconfirmed claims, including from a widely-cited “monitoring group”, have asserted hundreds of casualties and more than 100,000 people fleeing the area. Both sides are claiming victories, and there are also reports of the Kurdish militia YPG joining the fight against ISIS.

An Islamic Front spokesperson, speaking to Syria Direct, has warned that ISIS could take control of much of Deir Ez Zor:

In the coming days, if ISIS’s army is revitalized, grows stronger and is able to gain the allegiances of tribes in the area, then they could at any moment take full control over the province, especially since they have occupied the only entrance into the city and have control over the resources like the Jafra and Konika oil fields.

ISIS currently has complete control over the western suburbs of the province and the right bank of the Euphrates, as well as partial control over al-Ma’amel and Douar al-Ma’amel, the northern suburbs and the south bank of the Khabur river. They have been besieging Deir e-Zour after the withdrawal of all [rebel] troops from the western suburbs.

The spokesman says capture of the territory would not only give ISIS control over vital resources but also connect its areas of influence in Syria and Iraq: “Controlling Deir e-Zor creates a wide-open path from Iraq to Damascus, Hama, Homs, Idlib and Aleppo, and even to a-Raqqa and Hasaka, since only the desert separates them.”

The Islamic Front’s representative confirmed the departure of “thousands” of residents to villages on the western bank of Euphrates.

(PHOTO: Street in Deir Ez Zor, April 2014 — Mohamed al-Khalif/Reuters)