Relief agencies have evacuated 500 wounded people from four besieged Syrian towns in the first major evacuation in the country since December.
The evacuees, who were "in urgent need of life-saving medical attention," according to the United Nations, were bussed out of the towns late on April 20.
Exactly 250 of them were brought out of the rebel-held towns of Madaya and Zabadani, near the Lebanese border.
The same number were evacuated from the government-held towns of Foah and Kafraya in the norththwest.
Jan Egeland, chairman of a UN humanitarian task force in Syria, hailed "the largest evacuation ever from the besieged areas of Syria" as a "breakthrough."
The operation has been carried out by the Syrian Red Crescent in cooperation with the UN and the International Committee of the Red Cross.
Based on reporting by AFP and the BBC