Syria’s army, backed up by fighters from Lebanon’s Hezbollah, have reportedly made big advances against insurgents in a key border region.
The development in the Qalamoun area would be a boost for President Bashar al-Assad after several defeats for his forces elsewhere.
Intense battles are raging on several fronts, including around Idlib and near the world heritage site of Palmyra.
Rebels have reportedly attacked and stormed a military checkpoint in the Idlib province, blowing up a nearby tunnel.
But there is real concern about the advance by ISIL militants on a government-held area near Palmyra, which is listed by UNESCO.
The fighters, who call themselves Islamic State, have already destroyed ancient monuments in Iraq.
The militants have been stepping up their offensive on government and rebel-held areas.
Photos of Palmyra: