In this photo released by the Syrian official news agency SANA, residents gather near a green government bus for evacuating from eastern Aleppo, Syria, Thursday, Dec. 15, 2016. The Russian military said over 1,000 people have been evacuated from Aleppo under a cease-fire deal reached with Syrian rebels. France's ambassador to the United Nations says international observers should monitor the safe evacuation of civilians and fighters from the war-torn Syrian city of Aleppo. (SANA via AP)
In this photo released by the Syrian official news agency SANA, residents gather near a green government bus for evacuating from eastern Aleppo, Syria, Thursday, Dec. 15, 2016. The Russian military said over 1,000 people have been evacuated from Aleppo under a cease-fire deal reached with Syrian rebels. France's ambassador to the United Nations says international observers should monitor the safe evacuation of civilians and fighters from the war-torn Syrian city of Aleppo. (SANA via AP) Credit: Uncredited

Beirut — Buses and ambulances rolled out of the last rebel districts in the Syrian city of Aleppo on Thursday as part of a major evacuation that ended the opposition’s battle for its greatest stronghold.

They left behind one of the world’s great ancient cities, now shattered by brutal government-allied air strikes that have killed thousands of people and reduced infrastructure to rubble.

Reports from aid groups and the Turkish government suggested that more than 2,000 people — including hundreds of rebel fighters — had left in the early waves, monitored by the army of Syrian President Bashar Assad and his Russian allies.

Aerial video from eastern Aleppo, a part of the northern metropolis captured by the rebels in 2012, showed green school buses stretching out through the remains of once-crowded streets. In images posted to social media, families gathered at pickup points, huddling in near-freezing cold as they waited for rescue.

Some families burned heirlooms rather than leave them behind for pro-government forces. Others left graffiti messages of anger, sorrow and even hope of returning.

If all goes according to plan — never a certainty in Syria’s multilayered conflict — around 50,000 people are expected to leave before the end of the week, a senior Turkish official told the Reuters news agency.

Many aspects of the deal remain unclear, however, including what will happen to anti-government fighters who choose to leave.

Their destination is the northwestern province of Idlib, which is dominated by hard-line Islamists and likely to soon become a new focus of the government’s military campaign.

The United Nations Syria envoy, Staffan de Mistura, warned Thursday that without a return to political negotiations, the area risks a similar fate.

“Without a political agreement or cease-fire, Idlib will be the next Aleppo,” he told reporters in Geneva.

Pro-Assad forces pushed rebel fighters into a sliver of territory during a relentless month-long offensive. Although Aleppo’s evacuation will not halt the fighting in Syria, it marks a huge blow – tactically and symbolically – to rebel groups now staring down the barrel of defeat.

The city now falls to the control of Syrian government forces — aided by Russia and Shiite militias backed by Iran — handing victory to Assad.

On Thursday, Assad hailed their victory as “the writing of history.” But those leaving Aleppo saw only misery and disappointment, as the West and its allies struggled to find ways to aid rebels or deter Syrian forces.

“You don’t understand what we have lived through here. Death hung above us. The world turned their backs,” said Mohamed al-Halabi, an electrician whose entire family was killed when an airstrike destroyed his workshop.

“Maybe today, finally, they will help us,” he added.