A second convoy of 50 aid trucks set off from Damascus for the besieged Syrian town of Madaya Thursday, an eyewitness told Reuters. Monday marked the first time since October that aid convoys were allowed to enter Madaya, after humanitarian groups struck a deal with the Syrian government last week.

The United Nations reportedly said that it has received credible reports of several people dying of starvation in the rebel-held town near the Lebanese border, where about 40,000 people have been trapped. 

Since last month, at least 23 people, including six children under the age of one, have died from starvation at a Doctors Without Borders-supported health center in Madaya.

"These harrowing accounts of hunger represent the tip of an iceberg," Philip Luther, the Middle East director for Amnesty International, said in a report last week.

“Syrians are suffering and dying across the country because starvation is being used as a weapon of war by both the Syrian government and armed groups,” Luther said.