Some 800 women, children and elderly civilians trapped in the besieged town of Moadamiyet al-Sham, southwest of Damascus, have been evacuated, activists said Wednesday.

Supervised by the Red Crescent, they were escorted from the rebel-held town a day earlier in coordination with the regime.

"Eight hundred civilians were evacuated yesterday," said Wassim al-Ahmad, of the town's local council.

Activists had earlier reported the evacuation of 500 people.

"All sides, without exception, took part, including the opposition as represented by the National Coalition, the regime and the international community," an opposition activist in Moadamiyet al-Sham said.

Television footage showed the evacuees clutching a few personal belongings as they streamed out of the town along a dusty avenue, with Red Crescent staff carrying one elderly man and assisting another too frail to walk alone.

Moadamiyet al-Sham has been under a suffocating army siege for nearly a year.

Rights groups and activists have reported widespread malnutrition there, particularly among children, because of a total blockade on the entry of food and other vital goods.

The army shells the town daily, and clashes rage on its outskirts, and the town was the scene of one of the army's chemical attacks near Damascus on August 21, which killed hundreds of people.

Activists there issued a statement saying they would have preferred humanitarian assistance to be brought in instead, "but we did not have a choice."

The civilians who left have now joined millions of people internally displaced by the war.

They are being moved to "camps set up by the regime in the outskirts of Qudsaya (near Damascus), in coordination with the Red Crescent," said the activists.

According to Ahmad, "there are some 6,000 civilians left in the town".

Tuesday's evacuation was the second operation of its kind since October 12, when 3,000 civilians were taken out on buses.

The opposition and UN humanitarian chief Valerie Amos have both called for humanitarian corridors into Moadamiyet al-Sham.