By Ellen Francis and Lisa Barrington

BEIRUT (Reuters) – Buses carrying Syrian civilians and fighters began leaving the last rebel-held enclave of Aleppo on Wednesday after being stalled for a day, aid officials and pro-government media reports said.

Obstacles hindering evacuations from east Aleppo and from two villages besieged by rebels outside the city had been overcome and the operation would be completed within hours, according to a news service run by the Lebanese group Hezbollah, an ally of the Syrian government.

The eventual departure of the thousands left in the insurgent zone will hand full control of the city to President Bashar al-Assad, the biggest prize of Syria’s nearly six-year-old civil war.

“Buses are now moving again from east Aleppo. We hope that this continues so that people can be safely evacuated,” a U.N. official in Syria told Reuters, as snow began to fall on Aleppo.

People had been waiting in freezing temperatures since the evacuation hit problems on Tuesday, when dozens of buses were stuck in Aleppo and the evacuation of the two Shi’ite villages, al-Foua and Kefraya, also stalled. Rebels and government forces blamed each other for the hold-up.

Charity Save the Children said heavy snows were hampering aid efforts.

“Our partners are trying to treat injured children who have fled Aleppo but the situation is dire. Many have had to have limbs amputated because they did not receive care on time, and far too many are weak and malnourished,” a statement said.

One 5-month-old girl had two broken legs, a broken arm and an open wound in her stomach, the statement said.

Many of those who had escaped Aleppo were sleeping in unheated buildings or tents in sub-zero temperatures. Children have been separated from their parents in the chaos as they run to get food when they get off the buses, the charity said.

EVACUATION PLAN

With obstructions to the evacuation plan apparently overcome, the Hezbollah news service said 20 buses carrying fighters and their families had moved from east Aleppo on Wednesday toward rebel-held countryside. Syrian TV said four buses and two ambulances arrived in government-controlled parts of Aleppo from al-Foua and Kefraya.

Government forces had insisted the two villages must be included in the deal to bring people out of east Aleppo.

So far, about 26,000 people have been evacuated from Aleppo, according to aid officials. A U.N. official said 750 people had so far been evacuated from al-Foua and Kefraya.

Aleppo’s rebel zone is a wasteland of flattened buildings, concrete rubble and bullet-pocked walls, where tens of thousands lived until recent days under intense bombardment even after medical and rescue services had collapsed.

Rebel-held parts of the once-flourishing economic center with its renowned ancient sites have been pulverized in a war which has killed more than 300,000, created the world’s worst refugee crisis and allowed for the rise of Islamic State.

But in the western part of the city, held throughout the war by the government, there were big street parties on Tuesday night, along with the lighting of a Christmas tree, as residents celebrated the end of fighting.

The Syrian army has used loudspeakers to broadcast warnings to rebels that it was about to enter their rapidly diminishing enclave and told them to speed up their evacuation.

Control of Aleppo would be a major victory for Assad, and his main allies Iran and Russia, against rebels who have defied him in Syria’s most populous city for four years.

U.N. MONITORS EVACUATION

The United Nations had said it had sent 20 more staff to east Aleppo to monitor the evacuation.

“Some have arrived yesterday and more will be arriving today and in the coming days,” Jens Laerke, U.N. spokesman in Geneva told Reuters.

Various problems have beset the evacuation, with estimates of how many have left and how many remain varying widely.

Assad’s government is backed by Russian air power and Shi’ite militias including Lebanon’s Hezbollah movement and Iraq’s Harakat al-Nujaba. The mostly Sunni rebels include groups supported by Turkey, the United States and Gulf monarchies.

For four years, the city was split between a rebel-held eastern sector and the government-held western districts. During the summer, the army and allies forces besieged the rebel sector before using intense bombardment and ground assaults to retake it in recent months.

Russian air strikes were the most important factor in Assad’s triumph. They enabled his forces to press the siege of eastern Aleppo to devastating effect.

On the ground, Shi’ite militias from as far afield as Afghanistan played an important role for Assad.

Despite victory in Aleppo, Assad still faces great challenges in restoring the power of his state. While he controls the most important cities in western Syria and on the coast, armed groups including Islamic State control swathes of territory elsewhere in the country.

(Additional reporting by Stephanie Nebehay; Writing by Angus McDowall and Peter Millership; Editing by Giles Elgood)