As many as 60 armed insurgents were killed Monday by government troops in Syria's northern province of Aleppo, an inflamed battleground in the country's 18-month-old crisis, pro-government radio Sham FM said.

The insurgents, including a Saudi national named Saudi al- Harithi, who headed the group, were killed in an operation of Syrian troops in al-Sukkari area of Aleppo, said the report.

Meanwhile, the oppositional Britain-based Syrian Observatory for Human Rights said the Aleppo council building was bombarded earlier Monday by rebel fighters, which led to the panic of employees in the building.

No one was killed in the attack, but injuries were reported in addition to property damage.

The battles in Aleppo, Syria's largest city and commercial hub, have been raging since Thursday when the armed rebels announced the commencement of a "decisive battle" in a bid to bring down Aleppo.

The intense fighting has started to threat the old heritage of the city as some 500 old shops in the ancient marketplace were reported to have been fully burnt.

The observatory placed the death toll of Monday's violence at 156, including 84 unarmed civilians, 28 rebel fighters, five defectors and 39 government soldiers. Such toll can not be checked independently.