Aid workers witnessed a "severely malnourished" boy of 16 die from starvation as they delivered emergency food aid to the besieged Syrian town of Madaya, the UN children's fund Unicef has said.
It also confirmed that its team had witnessed "severe malnutrition" among children in the town in a statement.
A number of deaths had previously been reported among residents of the town, who were left trapped and starving for months by armed supporters of the Syrian government and their allies Hezbollah.
Children were said to be surviving on jam and water, while others turned to cooking leaves to ward off starvation.
Deliveries of food aid have been made in recent days after the UN managed to arrange safe passage to deliver emergency humanitarian supplies.
Aid workers had warned that the siege was likely to have taken a heavy toll on the health of those living there, with children and the elderly expected to be among the worst affected.