In a residential complex in northern Aleppo, an area which until early last week was still under the control of rebel troops, Salem al-Naser, a dentist, found himself trapped in a badly damaged building where he had been seeking refuge from the pounding of artillery fire, rockets and missiles.

"I don't even know how to describe the objects falling around us," he told Alison Meuse, an NPR reporter who approached him for an interview aired in the Morni