Fighting is reported to be intensifying across Syria, with the city of Aleppo in its second day of clashes.
The fighting was centred on the Salah al-Din district, but had also spread to Sakhur and Haydariya, the Syrian Observatory for Human Rights reported.
The BBC reports Aleppo has so far been spared the daily bloodshed seen in other cities since the uprising began in March 2011.
The violence came a day after the UN Security Council voted to extend the UN observer mission for a "final" 30 days.
A resolution stated that after that period the monitors would leave if they were unable to carry out their job of verifying the peace plan brokered by the UN and Arab League's special envoy, Kofi Annan.
Their mandate may be renewed if the use of heavy weapons ends.
The observers' work has been mostly suspended since June because of the escalating violence, which reportedly left more than 300 people dead on Thursday and another 200 on Friday.
On Saturday, UN Secretary General Ban Ki-moon urged the Security Council to forge a united way forward and exercise its collective responsibility.
Mr Ban also said he would send his Under-Secretary General for Peacekeeping Operations, Herve Ladsous, to Syria and had asked his top military adviser to take charge of the observer mission.
The surge in violence has trapped millions of Syrians and turned sections of the capital, Damascus, into ghost areas, while sending thousands of refugees fleeing to neighbouring countries.
The Syrian Observatory for Human Rights said at least 130 people were killed on Saturday across the country, including 64 civilians.
