The rebel Free Syrian Army now controls much of the country: its fighters are struggling for possession of Aleppo, the commercial capital. The FSA claimed to be delaying the regime's advance on the city at the end of a day of intense fighting. Mr Assad's forces had been unable or unwilling to enter the key district of Salaheddin, despite reinforcements of thousands of troops and hundreds of tanks, according to rebel spokesmen. The insurgents were also encircling government troops in the northern half of Aleppo. They believe the army's inability to fully employ tanks in built-up areas has blunted its assault.