Besieged residents and Syrian opposition combatants and non-combatants began evacuating the Damascus suburb of Daraya on Friday, witnesses told Reuters. The exodus takes place during one of the longest stand-offs in Syria’s five-year war began.

Syrian Opposition and regime forces had agreed to a truce on Thursday as to evacuate the town, which the pro-regime army has besieged since 2012.

The U.N. said only one shipment of aid has reached the area since then.

A Reuters witness saw six buses leaving the town. Footage on state television showed buses carefully driving past a large group of soldiers through streets lined with rubble.

A first group was later reported to have arrived at a housing center in Herjalleh, another suburb west of Damascus, by Syrian state television.

A Syrian Army general told reporters in Daraya that around 300 families of opposition fighters would leave the town on Friday, and in total around 700 fighters and 4,000 civilians would be evacuated by Saturday.

The plight of civilians in Daraya and other besieged areas has long been of concern to the United Nations, which has condemned the use of starvation as a weapon by both sides in the conflict.

But the United Nations was not consulted on Daraya’s evacuation plan and U.N. Special Envoy Staffan de Mistura and U.N. humanitarian coordinator Stephen O’Brien, voiced deep concern about it on Friday.

They said civilians should be evacuated only if their safety could be guaranteed and it was on a voluntary basis.

There have been previous deals to allow similar evacuations of besieged fighters and civilians, or to let people return to their homes after ceasefires were agreed.

In February, around 4,000 people returned to their south Damascus neighborhood after a ceasefire deal, and in December hundreds of fighters and their families were evacuated from two besieged areas in northern and western Syria.