Damascus, July 4 (IANS): The Syrian army and the Hezbollah group on Saturday unleashed a broad offensive against a rebel-held resort town northwest of capital Damascus and close to Lebanon's borders, media reports and a source familiar with the assault told Xinhua news agency.

The Syrian army and the allied Lebanese Hezbollah group started a massive attack against the city of Zabadani from different routes on Saturday under cover of artillery and aerial bombardment that targeted all of the rebels' positions in that resort town in the western part of the rugged Qalamoun region near Lebanon, the source said.

Media reports said the assault on the city came just a couple of days after the rebels in Zabadani announced the start of a battle to break the government troops-imposed siege on the city.

The rebels' attempt to break the siege failed as the Syrian forces started a swift operation, isolating Zabadani from the adjacent town of Surghaya, where the rebels also hold sway.

Heavy shelling continued over the last couple of days against the rebel positions in Zabadani, Sughaya and the nearby town of Madaya, targeting a training camp and a command centre of the Al Qaeda-linked Nusra Front.

Zabadani is located 45 km northwest of Damascus and is only 11 km from the Lebanese border. The city has at least 1,500 rebels.

Hezbollah and the Syrian forces have been busy recently dislodging rebels from the eastern parts of the Qalamoun mountains, and their battle in Zabadani in the west was expected after both the allies retook almost all the towns in eastern Qalamoun.