Syrian government troops and rebels were locked on Friday in the fiercest fighting seen in the country's second city of Aleppo since a 16-month uprising began, the Syrian Observatory for Human Rights said.

"Violent clashes are taking place in the Salaheddin, Azimiyeh, Akramiyeh and Ard el-Sabbagh neighbourhoods between the regular army and the rebels," the UK-based activist group said.

The Observatory said three rebels and two civilians were killed in the city on Friday. The rebels were killed in fighting with government troops and one civilian was killed by the army, it said.

The second civilian was killed when security forces opened fire on  demonstrations that the Observatory said took place in several parts of Aleppo.

The Britain-based Observatory said the clashes began on Thursday night. The clashes came amid reports of fighting in several neighbourhoods of Damascus and after the Observatory reported 302 people killed across the country on Thursday, the bloodiest single day in a 16-month anti-regime revolt.

A commercial centre, Aleppo had initially been largely excluded from the protests and subsequent uprising against the regime of President Bashar al-Assad.

[Source: AFP]