Syrian rebels are battling President Bashar al Assad’s forces near the government's main intelligence headquarters in Aleppo, according to reports.
Government helicopter gunships have also bombarded the north Damascus district of Barzeh with rockets, say residents and rebel activists.
In the west of the city Syrian rebels are reported to have withdrawn from the district of Mezze after coming under heavy aerial and ground bombardment from President Assad’s forces.
The rebels are also claiming they have captured the Bab al-Salam border post with Turkey.
There have also been reports of government fighting in the Eastern aera of Deir al-Zor where witnesses are claiming government forces are attacking rebels with artillery, rockets and helicopter gunships.
One witness counted 200 shells hitting the Ordi and Old Airport districts of the city, which lies 270 miles northeast of the capital Damascus.
It was the heaviest reported bombardment since the army stormed Deir al-Zor a year ago to crush street protests against President Assad.
The attacks come as thousands of Syrians flee to Lebanon to escape the fighting . The UN says at least 30,000 people have crossed over the main border point at Al Masna - just an hour's drive from the Syrian capital - in the past few days.
The latest round of fighting comes after rebel attacks on the national security building injured President Assad's brother in law and killed the defence minister.
More than 19,000 people in Syria are reported to have lost their lives since the start of hostilities 16 months ago, according to the UK based Syrian Observatory for Human Rights.