UN convoys trying to reach besieged Syrian towns this week

United Nations aid convoys were unable to deliver life-saving supplies to four besieged Syrian towns of Zabadani, Foua, Kefraya and Madaya on Monday due to "security concerns" but will try again on Thursday, a U.N. spokesman said.

Jens Laerke, spokesman of the U.N. Office for the Coordination of Humanitarian Affairs, said a separate aid convoy would go to the town of Bloudan in Rural Damascus on Wednesday.

A humanitarian task force composed of major and regional powers meets again in Geneva on Thursday to discuss improving access to more than 4 million civilians trapped in both besieged and hard to reach areas, U.N. spokesman Ahmad Fawzi said.