(reuters) -- The army and the allied forces advanced east and south of the rebel held bastion of Beit Jin backed by some of the heaviest aerial bombing and heavy artillery shelling since a major assault began over two months ago to seize the area, rebels said.

The Syrian army said it had encircled the village of Mughr al Meer at the foothills of Mount Hermon as troops moved towards Beit Jin amid fierce clashes.

The enclave is the last rebel bastion left in the south west of Damascus known as the Western Ghouta that had since last year returned to government control.

A western intelligence source confirmed rebel reports that Lebanese Hezbollah group was playing a major role in the ongoing battles.