The "Islamic State of Iraq and Syria" (ISIS) has expanded its presence in the border area of Idlib and Hama in north-western Syria, where it has re-entered a group of villages that previously had been under its control.

The sudden withdrawal of ISIS rival Tahrir al-Sham from many positions and towns in the wake of a Syrian regime offensive has cleared the way for the group's expansion, activists told Diyaruna.

At dawn Wednesday (January 10th), ISIS managed to advance towards the area separating the provinces of Idlib and Hama, seizing control of several villages.

These include Tlaihan, al-Musaytba, Abu Kahf, al-Sakri and Umm Sahrij in northern rural Hama and southern rural Idlib, activist Motaz Imran of the Hama province town of Halfaya told Diyaruna.

The areas ISIS re-occupied had been under the control of Tahrir al-Sham, a rival extremist alliance dominated by the former al-Nusra Front (ANF).

They were considered important military positions, Imran said, but the alliance withdrew from them completely, enabling ISIS to re-enter that area.

After the new advance, "ISIS now controls more than 50 towns and villages throughout rural Idlib and Hama provinces", Imran said.

Residents of this area have fled to relatively safe areas in Idlib, where they have been caught between the fire of ISIS and that of the Syrian regime, which also is deployed on the area's outskirts, he said.