Convoys carrying urgently-needed aid have reached four besieged areas of Syria, the UN and aid agencies said.
Trucks reached rebel-held Muadhamiya and Madaya, near Damascus, and pro-government northern villages of Foah and Kefraya on Wednesday. Another town, Zabadani, is also due to receive aid.
Almost 500,000 people live in besieged areas in Syria, according to the UN.
The deliveries are part of an agreement that world powers hope will lead to a "cessation of hostilities" by Friday.