Fighting continued for the third day in the capital, Damascus, as Syria's rebels announced the launch of a "Damascus volcano" offensive against Alawite regime forces, witnesses told the AFP news agency.

"Machinegun fire was heard in the Sabaa Bahrat square, and members of the security forces, armed with Kalashnikovs, ran across the square," site of the country's central bank, one witness said.

Heavy machinegun fire rocked in center of the city, while shooting was also reported in Baghdad Street, a main road near the square. Two entry points into the square were briefly closed, and then reopened to traffic.

The shots were fired as fighters in anti-regime neighborhoods of the capital clashed violently with the Alawite army, while regime forces deployed helicopters to fire into several districts.

A column of smoke could be seen on Tuesday billowing from the Midan district near the center of Damascus, which has been pounded by Alawite regime troops since Monday.

"I can hear shelling, explosions and gunfire every once in a while," a Kfar Souseh resident told Al Jazeera in the early hours of Tuesday.

Troops deployed armored vehicles near the historic neighborhood of Midan, and activists said residents were fleeing nearby Tadamon.

The fighting briefly closed the highway linking the capital with Damascus International Airport on Monday.

On the video footages, posted online, you can see how the Syrian Mujahideen fired from anti-tank grenade launchers from their barricades.

http://www.youtube.com/watch?v=Gia_eofYTmI&feature=relmfu