Syria's Red Crescent said on Saturday it delivered some food and medical aid to rebel-held areas of Homs city that have been under siege by government troops for more than 600 days.
"Although the team was shelled and fired upon we managed to deliver 250 food parcels, 190 hygiene kits and chronic diseases medicines," the Syrian Red Crescent said on Twitter.
In an earlier tweet, the Red Crescent also said all its workers and the UN staff with them had left the besieged Old City of Homs safely, with one aid truck driver having suffered a "minor injury."
State news agency SANA quoted Homs Governor Talal al-Barazi as saying "the humanitarian aid was distributed in the neighbourhoods of Bustan al-Diwan and Hamidiyeh, under the supervision of a Red Crescent team and the United Nations."
An aid convoy delivering the much-needed relief to some 3,000 people trapped in rebel-held areas of Homs had been due to enter the besieged neighbourhoods early Saturday, as part of a UN-supervised deal involving a three-day "humanitarian pause" in the fighting from 6:00 am (0400 GMT) to 6:00 pm (1600 GMT).
But the convoy was fired on with mortars and small arms during the early afternoon, with rebels and the regime trading accusations over who was behind the gunfire, after morning shelling had also hit the Old City neighbourhood, in violation of the truce.
The violence prompted a delay of several hours in the delivery of aid to districts where people have been surviving for many months on little more than wild herbs and olives.
But on Saturday night the Red Crescent distributed a photograph showing a group of people in a devastated street gathered around an aid truck marked with the humanitarian organisation's crescent moon logo.
Footage distributed by activists in Homs and apparently shot in the city showed one aid truck being fired on. It was not possible to independently verify the footage.
The Syrian Observatory for Human Rights said five people had been killed, including a rebel commander, and 20 others injured in several rounds of shelling across besieged Homs Saturday.
Activists in areas under siege say the ceasefire has barely held, with one describing Friday's evacuation of 83 civilians as a "miracle" amid the ongoing violence.
The evacuation of scores more civilians, mainly women and children, is set to continue on Sunday.