DAMASCUS - The rebel groups in the town of Khan Shaykhun in the northwestern province of Idlib and other key towns in the adjacent countryside of Hama province were forced to withdraw as a result of the offensive by the Syrian army in that region, a war monitor reported.

The rebel groups withdrew from Khan Shaykhun in the southern countryside of Idlib for fear of being fully besieged by the Syrian army, said the Syrian Observatory for Human Rights.

The rebels also pulled out from other key towns to the south of Khan Shaykhun, including al-Latamneh, Kafr Zita and Morek, which are located in the northern countryside of Hama province, said the UK-based watchdog group.

The aforementioned areas had been key bastions for rebel groups in Idlib and Hama provinces.