Related reading:

UNITED NATIONS, Dec. 19 (Xinhua) -- The UN Security Council on Monday unanimously adopted a resolution to send UN observers to monitor evacuations in Syria's war-torn Aleppo.

The resolution requests the UN to carry out adequate, neutral monitoring and direct observation on evacuations of civilians and fighters from eastern Aleppo.

The 15-nation council also demands that all parties allow safe and unhindered access for the UN in order to ensure that humanitarian assistance reaches people in need.

The council members asked the UN secretary-general to take urgent steps to make arrangements and report to the council within five days of adoption of the resolution.

Once Syria's commercial hub, Aleppo has been divided roughly in two since 2012, with western parts under government control and eastern districts held by rebels.

The situation in Aleppo has deteriorated rapidly after a truce accord collapsed in September.

As part of a deal concluded by Russia and Turkey, buses carrying rebels and their families have started leaving Aleppo since Thursday.

The evacuation was once suspended when the rebels didn't allow people from Kafraya and Foa to leave but was resumed on Saturday after the rebels agreed to allow civilians to go.

The whole evacuation came as the Syrian army has captured 99 percent of eastern Aleppo over the past three weeks, as part of a major offensive aiming at driving out the rebels from the city.