Smoke and fire mark Syrian cities

Smoke pours out of a damaged building in Aleppo.

Amateur video which could not be independently verified by Reuters appears top show the aftermath of a shelling in Syria's largest city.

More footage appears to show rebel forces entering a government barracks where they destroy images of the Assad regime.

The weeks-long fighting for control of Syria's commercial hub appears to be grinding on with no decisive outcome for either side.

More footage purportedly from Damascus shows flames coming out of a home.

The Syrian Observatory for Human Rights says 170 people were killed across Syria on Friday. They say more than 23,000 people have died in Syria since the uprising began last March.