Syrian forces with their Lebanese Hezbollah allies are carrying out a major offensive against rebels holding the strategically important town of Zabadani, state TV says.

Zabadani, north-west of the capital, Damascus, is the last significant town held by Sunni Muslim rebels in an area close to the Lebanese border.

Hezbollah's al-Manar TV showed large clouds of smoke from explosions caused by artillery and air strikes.

Reports say civilians have fled.

The rebels remaining in the town are thought to have been reinforced by hundreds of fighters who fled hills on the nearby Lebanese border. They were ejected from the hills by Hezbollah, a Shia Muslim force.

Attempts to negotiate a peaceful outcome to the conflict in Zabadani failed, al-Manar reported.

The battle for the town had been looming for some days, the BBC's Jim Muir reports from Lebanon.

Zabadani is strategically placed near the main highway linking Damascus to Beirut and rebel control there has long been a thorn in the Syrian government's side, our correspondent adds.

State TV quoted a Syrian army source as saying its forces were "making headway on several fronts" and the rebels had suffered heavy casualties.
Syrian forces close in on rebel-held Zabadani - BBC News