Syria: Aleppo 'massacre' feared by US
26 July 2012 Last updated at 22:39 BST
The US state department has said it fears a massacre in the Syrian city of Aleppo.
Troops and tanks have been converging on the city which is the commercial heart of the country.
Aleppo has seen intense fighting between rebel forces and government troops in recent days.
Jeremy Bowen reports.