Activists and opposition groups say Syrian troops and rebels have clashed for a second day in the northern city of Aleppo.
They say the overnight clashes with heavy machine guns were some of the fiercest to date in the heart of Syria's northern commercial hub.
Aleppo has been largely shielded from the violence that has plagued other Syrian cities over the course of the uprising
against President Bashar Assad,
now in its 17th month.
Aleppo-based activist Mohammad Saeed said dozens of rebels from the Free Syrian Army were now in the city. He said fighting was mostly in the Salaheddine district in the city center.
Funeral of Assad's security chiefs (Photo: AFP, HO, SANA)
The Local Coordination Committees activist network and the Britain-based Syrian Observatory for Human Rights said Friday's fighting forced many residents to flee to safer areas.
Overnight Saturday, Syrian government forces pounded rebels in Damascus, battling to reverse opposition gains in the aftermath of the assassination
of Assad's security chiefs.
Army helicopters and tanks aimed rockets, machineguns and mortars at pockets of rebel fighters who have infiltrated the capital this week in an operation they call "Damascus Volcano".
The Syrian Observatory for Human Rights, an opposition group which monitors the violence in the country, said 240 people had been killed across Syria on Friday, including 43 soldiers.
The Observatory's combined death toll over the past 48 hours stands at 550, making it the bloodiest two days of the 16-month-old uprising against Assad.
On Wednesday a bomb
killed four members of the president's narrow circle of kin and lieutenants, including his powerful brother-in-law, defense minister and intelligence chief.
"The regime has been rudderless for last three days. But the aerial and ground bombardment on Damascus and its suburbs shows that it has not lost the striking force and that it is re-grouping," opposition activist Moaz al-Jahhar said by phone from Damascus.
In the days since, rebels have pushed deep into the heart of the capital and seized control of other towns. On Thursday, they captured three border crossings with Iraq and Turkey, the first time they have held sway over Syria's frontiers.
AP and Reuters contributed to this report