Aid teams on Sunday evacuated at least 65 civilians from besieged districts of Homs city, Syrian state media said, accusing rebels of firing on their convoys.

"Sixty-five civilians, all children, women and elderly men, were evacuated from the Old City of Homs, in compliance with an agreement between the UN and the governor of Homs," said the official news agency SANA.

State television said the operation took place under fire from "armed terrorist groups," using the regime's term for rebels.

The Syrian Observatory for Human Rights and activists said fire hit the rebel-held, besieged district of Qarabis in Homs, where dozens of civilians were gathered for evacuation by the UN.

"Dozens of civilians were evacuated," said the Britain-based Observatory, adding that fire from unknown sources hit parts of the Qarabis neighbourhood.

Activists said a gathering point for civilians was hit by mortar rounds launched from pro-regime districts bordering the besieged neighbourhoods where civilians have been trapped for more than 600 days.

Sunday's evacuation was the second in three days, since a UN-brokered truce for army-besieged districts of Homs was to have come into effect on Friday.

But on Saturday, shelling and gunfire hit a Syrian Red Crescent aid convoy, killing five residents of the rebel-held neighbourhoods and wounding 20 others.