Damascus. Aid workers have returned to the besieged central Syrian city of Homs, a day after trucks carrying supplies came under fire, evacuating civilians and delivering food and medicine.

More than 600 civilians have been evacuated from the Old City since Friday, with the majority coming out on Sunday. But the process has not been without danger.

Activists told Al Jazeera that shelling struck civilians who were preparing to be evacuated in the district of Al Qarabis on Sunday. Several people were said to have been killed and a number of others injured as a result of the incident. 

Khaled Erksoussi, the head of operations at Syrian Arab Red Crescent, told Associated Press on Sunday that the agency would try to evacuate more civilians from rebel-held areas in Homs, in line with a United Nations-brokered agreement on a three-day truce. Syrian forces loyal to President Bashar al-Assad have prevented the entry of food and medical aid into parts of Homs for more than a year.

Erksoussi said 83 civilians have been evacuated since Friday, when the truce went into effect. It was broken a day later, leaving an aid worker wounded, he said in a phone interview from Damascus