ANTAKYA, Turkey — A three-day humanitarian cease-fire in the Syrian city of Homs was supposed to be a small breakthrough, a moment of relief for civilians trapped in a grim civil war.
But mortar rounds and gunfire struck near aid convoys, damaging vehicles and leaving victims lying in the streets. Snipers fired on civilians as they fled their besieged neighborhood. Others refused to leave, fearing a massacre of those left behind. Limited food made it in, and some of the nearly 700 people who reached safety said they had been surviving on one meal a day and that some of their neighbors had resorted to eating grass.
Though few expect the international peace talks that resume in Geneva today to end the war, many hope they will make life less brutal for ordinary Syrians by creating local cease-fires and opening up access to aid.
But what took place in Homs highlights the tremendous difficulties plaguing even modest humanitarian efforts, making it unlikely that the episode will emerge as a model to be repeated elsewhere.
The attacks on the aid convoys will also raise the stakes for the U.N. Security Council this week, as it weighs a draft resolution meant to force the government and rebel groups to permit aid organizations to operate.
The need for such pressure is dire, given the widespread use of siege tactics by both sides to turn hunger into a tool of war and weaken their enemies, often harming civilians as well.
The U.N.-brokered agreement on Homs, announced by the Syrian government last week, called for a three-day cease-fire to allow women, children and older men to leave a rebel-held part of the city while food was distributed to those who remained inside.
More than 600 people were evacuated from Homs on Sunday, a Syrian official said. The United Nations said 83 were evacuated on Friday.
The United Nations estimates that almost a third of the 9 million Syrians in need are in hard-to-reach areas and that access to many of them has been deliberately obstructed. While human rights groups say the government is responsible for most of the sieges, rebels, too, have tried to starve out their enemies.
"We have entire areas of the country where the ability to transport food and other materials is severely hampered because of deliberate blockades and constraints on trucks and convoys," Matthew Hollingworth, the director of the World Food Program's Syria program, said Sunday.