Rebel fighters and civilians wait to be evacuated from a rebel-held sector of eastern Aleppo, Syria December 18, 2016. Picture taken December 18, 2016. REUTERS/Abdalrhman Ismail

BEIRUT (Reuters) - The Syrian Observatory for Human Rights said Syrian President Bashar al-Assad took control of Aleppo city on Wednesday after the last batch of fighters was evacuated, but a U.N. official and rebels said evacuations were not yet completed.

Evacuations from the east of the city were continuing on Wednesday evening, a U.N. official in Syria told Reuters.

A spokesman for the Free Syrian Army rebel alliance, Osama Abu Zaid, they would carry on into the night and had been slowed by bad weather. He was speaking to the al-Arabiya al-Hadath news channel from the Turkey-Syria border.

Two other rebel officials also said the evacuation process was not complete. One said there were around 2,000 fighters and civilians still waiting to be transported out of the city, although it was difficult to gauge numbers.

An aid worker told Reuters that completion of the evacuation aboard buses was expected to be “imminent”.

The war monitor said only one small position on the western outskirts of the city remained in rebel hands. It said some 21,500 civilians had lost their lives in and around Aleppo during the battle for control of the city.