Madaya Syria: 'Grave peril of losing their lives'

The UN humanitarian chief has warned that some 400 people in the besieged Syrian town of Madaya need to be evacuated immediately, so they can receive life-saving medical treatment.

Stephen O'Brien's call comes after an international aid convoy delivered the first supplies there in months.

The United Nations said it had received credible reports of people dying of starvation.

Lyse Doucet reports from Beirut.