Rebel fighters walk near Red Crescent vehicles on their way to al Foua and Kefraya, in Idlib province, Syria Jan. 11, 2016. An aid convoy headed for a besieged Syrian town on Monday where thousands are trapped and the United Nations says people are reported to have died of starvation. REUTERS/Ammar Abdullah

BEIRUT — An hour's drive from the Syrian capital, some 20,000 people are under siege in the mountainous town of Madaya, its residents mostly housebound, hungry and cold, with temperatures below freezing. For the past six months, the town, which is under Syrian opposition control, has been subject to a government blockade. Monday marks the first time since October that aid convoys have been allowed to enter the besieged town, after humanitarian groups struck a deal with the Syrian government Thursday.

The agreement was part of a joint effort from the United Nations World Food Program, International Committee of the Red Cross and the Syrian Arab Red Crescent. Food and medicinal supplies that form the bulk of the 44-vehicle convoy are expected to sustain residents for up to one month, according to Agence France-Presse.

Until now, residents have been eating anything they can find, including donkeys and cats. One doctor in the city told CNN that he sees roughly 250 cases of people struggling with acute starvation every day, and he’s been able to give his patients only water and sugar. On Sunday, the doctor told CNN that five people, including one child, had died from starvation in the past 48 hours.

“Every day I wake up and start searching for food. I lost a lot of weight; I look like a skeleton covered only in skin. Every day, I feel that I will faint and not wake up again,” a Madaya resident identified by Amnesty International as Mohammad told the organization Sunday. I have a wife and three children. We eat once every two days to make sure that whatever we buy doesn’t run out. On other days, we have water and salt and sometimes the leaves from trees.”

At least 23 people, including six children under 1, have died from starvation at a Doctors Without Borders-supported health center in Madaya since Dec. 1. Upon entering the town Friday, Doctors Without Borders identified at least 250 people with severe, acute malnutrition.

"These harrowing accounts of hunger represent the tip of an iceberg," Philip Luther, the Middle East director for Amnesty International, said. “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.”

According to a U.N. estimate, Madaya is one of 15 besieged Syrian cities where at least 400,000 residents have little to no access to aid.

“Using starvation of civilians as a method of warfare is a war crime,” Luther said. “All parties laying siege to civilian areas — the government and non-state armed groups — must stop impeding relief supplies and allow immediate, unfettered access for humanitarian aid.”