Syria army attacks Aleppo as tanks move in
28 July 2012 Last updated at 17:26 BST
Syrian forces have launched ground and air attacks against rebels in parts of Aleppo, activists say.
The BBC's Ian Pannell, in Aleppo, has seen skirmishes, with a number of rebel fighters wounded or killed.
Rebels with the Free Syrian Army (FSA) say they have repelled an army incursion and destroyed tanks, but there is no independent verification.
Western nations have warned of a potential massacre in Aleppo, Syria's most populous city.
Mike Wooldridge reports.