Evacuations of areas under siege in northern Syria are picking up pace, with people in some rebel-held zones now being allowed to leave.

Evacuation of the last rebel enclaves in eastern Aleppo surrounded by Syrian forces restarted late on Sunday. Among those to have left is seven-year-old Bana Alabed, who had tweeted about conditions in the city.

A linked evacuation of government-held parts of Idlib province being besieged by rebels started early on Monday.

While civilians are being moved to safety in Syria, the UN Security Council is to discuss sending monitors to oversee the mass evacuations. There are hopes that countries divided on Syria’s fate will come to a rare agreement on the crisis.

Eastern Aleppo had been held by the rebels since 2012, but Syrian forces squeezed them into ever-smaller corners of the city, along with thousands of civilians, before evacuations started last week. Initial efforts collapsed on Friday, leaving civilians stranded without access to food and shelter and with almost no medical facilities. However, the operation to move civilians to other rebel-held territory restarted late on Sunday.

Turkey’s foreign minister said 4,500 civilians had left eastern Aleppo since midnight on Monday, bringing the number of evacuees to 12,000. The departure of Bana Alabed, whose home in eastern Aleppo was bombed and whose appeals for peace were heard worldwide, was confirmed by a Syrian-American aid organisation early on Monday. Among the people waiting to leave eastern Aleppo are sick and wounded children, said the children’s charity Unicef. Some young children have been forced to leave without their parents, the charity said.

After leaving Aleppo city, the evacuees will then be moved to parts of Aleppo and Idlib provinces.

The evacuation of civilians from eastern Aleppo was held up partly because of the need for another deal to go ahead.

Pro-government forces had demanded that people must be allowed to leave the mainly Shia villages of Foah and Kefraya in Idlib province, that are being besieged by rebels.

On Sunday, armed men set fire to buses that were about to transport the sick and injured from the villages. But Syrian state TV and the Syrian Observatory for Human Rights, a UK-based monitoring group, said early on Monday that 10 buses had now left the villages. The Observatory said 500 of the 4,000 villagers had left.

Several reports said the Jabhat Fateh al-Sham jihadist group, linked to al-Qaeda, was responsible for Sunday’s attack. But Hezbollah, the Lebanese militant group fighting alongside Syria’s government, said the buses were caught up in fighting between the jihadists and another Islamist rebel group that supported the evacuations.

The UN Security Council is said to have agreed a compromise to allow UN monitoring of the evacuation. It will be discussed at 09:00 (14:00 GMT) in New York. Russia, an ally of the Syrian government, had rejected a French-drafted plan to send UN officials to eastern Aleppo as “a disaster”, and formulated its own proposal. Diplomatic efforts to resolve the Syrian conflict have become “paralysed”, the BBC’s Middle East editor, Jeremy Bowen says.

While Monday’s talks may provide a consensus on monitors, he says, “because of the size of the crisis in Aleppo, there needs to be a big rethink on all sides about how the world approaches the Syrian war – that is in no way over”.