Six hundred Syrians left the ruins of the rebel-held center of Homs Sunday, escaping a siege of more than a year of hunger and deprivation.

The evacuees, mainly women, children and old men, were brought out by the United Nations and Syrian Red Crescent the third day of an operation in which the aid convoys came under fire and were briefly trapped in the city themselves.

Video footage from inside Homs showed scores of residents, carrying a few bags of possessions, rushing across an open expanse of no-man's land towards 10 white vehicles with U.N. markings, Reuters reported. Gunshots could be heard as they raced to the cars.

Dozens of people were wounded when they came under fire as they waited at an agreed-upon evacuation point in the rebel-held neighborhood of al-Qarabis, according to three activists based in Homs, who spoke to The Associated Press by Skype.

The Syrian activists said the gunfire came from a government-held neighborhood. The government news agency SANA also reported that civilians came under fire, but blamed "terrorists," its term for rebels.

"The last vehicle has arrived and the total is 611 people," Homs governor Talal Barazi told regional Arab broadcaster Al Mayadeen at a meeting point for evacuees outside the city.

The Red Crescent confirmed that around 600 people were evacuated and said 60 food parcels and more than a ton of flour were delivered to the Old City.

Barazi and Red Crescent officials said they were working to extend the operation beyond Sunday, the final day of a fragile and frequently violated three-day ceasefire in Homs.

Some of those who came out were men of fighting age who were not originally eligible to leave, Barazi said, but they had agreed to hand themselves over to police and judicial authorities and could win their freedom through amnesty.

Authorities suspect all men of fighting age to be part of rebel forces fighting to overthrow President Bashar Assad. 

Assad's authorities and rebel fighters have traded accusations of responsibility for attacks on Saturday which stranded the joint U.N.-Red Crescent team in central Old Homs for several hours after dark on Saturday.

UN humanitarian chief Valerie Amos has insisted that the UN and aid agencies will not be deterred by the weekend's violence, the BBC reported.

She said the events were "a stark reminder of the dangers that civilians and aid workers face every day across Syria."

The Red Crescent, in a joint operation with the UN, is trying to deliver food, water and medicine by truck to some 3,000 civilians in rebel-held areas.