An aid convoy carrying over 900 food parcels entered the besieged Yarmouk refugee camp in Damascus  on Thursday, an official from the UN agency for Palestinian refugees said."The distribution is on going. This is the first aid to enter the camp since January 21, by when UNRWA had distributed 138 food parcels," UNRWA spokesperson Chris Gunness said.The UN official said the delivery of around 600 food parcels  was encouraging and there was cooperation on the ground between different parties."We hope to continue and increase substantially the amount of aid being delivered because the numbers of those needing assistance is in the tens of thousands , including 18,000 Palestinians, among them women and children," he added.Besieged since June, the 18,000 remaining residents of Yarmouk camp have been forced to eat stray animals to survive amid critical food shortages. Once a refugee camp, Yarmouk  evolved generations ago into a bustling commercial and residential district, where both Syrians and Palestinians resided.In 2011, it was home to some 150,000 Palestinians registered in Syria after being forcibly displaced following Israel's establishment.When war spread to areas of Damascus in the summer of 2012, thousands of people from other parts of the capital fled to Yarmouk, swelling its population further.But Yarmouk soon became a war zone too, as Syrians taking up arms against President Bashar Assad's regime moved into the camp.Some Palestinians joined the rebels, others backed pro-regime groups, mainly the Popular Front for the Liberation of Palestine-General Command.In June, the army imposed a total blockade on Yarmouk, which covers an area of just over two square kilometers.Most residents had fled by then, but, according to the United Nations, 18,000 civilians remain.