Damascus - Heavy machinegun fire rocked Sabaa Bahrat square in central Damascus on Tuesday, witnesses said.
"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.
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 neighbourhoods of the capital clashed violently with the army, while regime forces deployed helicopters to fire into several districts.
Meanwhile a column of smoke could be seen on Tuesday billowing from the Midan district near the centre of Damascus, which has been pounded by regime troops since Monday.