Families had spent hours waiting in below-freezing temperatures, sheltering from the rain in bombed-out apartment blocks and waiting desperately for news on a new wave of departures.
After an agonising delay, the operation resumed on Monday under a complex agreement that will see regime forces exert full control over Syria's second city.
More than 7,000 people travelled in 100 buses out of Aleppo on Monday, while dozens more vehicles were preparing to leave, said Ingy Sedky, spokeswoman for the International Committee of the Red Cross (ICRC).
"We will continue throughout the day -- and however long it takes -- to evacuate the thousands more who are still waiting," Sedky told AFP.
The evacuees included seven-year-old Bana al-Abed, whose Twitter account had offered a tragic account of Syria's nearly six-year war, as well as 47 children who had been trapped in an orphanage.
Ahmad al-Dbis, who heads a team of doctors and volunteers coordinating evacuations, saw dozens of buses and ambulances arrive at the staging ground west of Aleppo.
He said the evacuees were in "a very bad state after waiting for more than 16 hours" at a regime checkpoint without being allowed off the buses.
The government had suspended evacuations on Friday, insisting that people also be allowed to leave two northwestern villages under rebel siege.
According to the ICRC and the Syrian Observatory for Human Rights, around 500 people left in a dawn convoy out of Fuaa and Kafraya.
'Terrible state'
The Observatory said at least 14,000 people, including 4,000 rebels, have left the opposition sector since the evacuations began on Thursday.
At least 7,000 remain, according to the Britain-based monitor.
A rebel representative said that hundreds of people would also be evacuated from Zabadani and Madaya, two army-besieged rebel towns near the border with Lebanon, as part of the deal.
Dbis said the Aleppo evacuees' departure was delayed for hours in temperatures well below freezing, compounding their plight from months of siege and bombardment by the army.
"They hadn't eaten, they had nothing to drink, the children had caught colds, they were not even able to go to the toilet," he told AFP.
He described families wrapped in several layers of coats getting off the buses, which then headed back to Aleppo to bring out more.
A young boy bit into an apple as aid workers distributed bottled water to his family.
The UN's children agency UNICEF said some of the children rescued from the orphanage had been in critical condition because of injuries and dehydration.
"Many vulnerable children -- including other orphans and children separated from their families -- still remain in east Aleppo and need immediate protection," it said in a statement.
The Humanitarian Relief Foundation (IHH), a Turkish NGO working in Syria, said seven-year-old blogger Bana had arrived at a camp for displaced persons in the northwest province of Idlib.
The Turkish news agency Anadolu later posted a short interview with Bana after her arrival, dressed in a warm coat and hat against the winter chill.
"In Aleppo the shelling was all over the place. We got out from the ruins because our house was bombed," she said shyly in Arabic, before turning towards her mother.
'Through hell'
Residents of east Aleppo -- a rebel bastion since 2012 -- had lived under four months of suffocating siege when Syria's army began its blistering assault in mid-November to retake the whole city.
"The people we are welcoming have been through hell -- the level of trauma they have experienced is impossible to describe or comprehend," said Casey Harrity of the international NGO Mercy Corps.
In an 11th-hour deal, regime ally Moscow and rebel supporter Ankara agreed on the evacuation of thousands of civilians and fighters from the last remaining opposition-held pocket in Aleppo.
Moscow, which has carried out an air war in support of the Damascus regime since September last year, had threatened to veto a UN Security Council draft resolution calling for monitors to oversee the protection of civilians.
But on Monday, the council unanimously adopted the French-drafted resolution in the first show of unity in months among world powers grappling with the Syria crisis.
The measure tasks the UN with carrying out "adequate, neutral monitoring and direct observation on evacuations from eastern Aleppo and other districts of the city".
It remained uncertain, however, whether the Syrian government would give the observers access to the city and allow operations there to come under international scrutiny.
The foreign and defence ministers of Russia, Turkey and Iran are due to meet in Moscow on Tuesday to discuss Syria.
In this photo released by the Syrian official news agency SANA, smoke rises in green government buses, in Idlib province, Syria, Sunday, Dec. 18, 2016. (AAP) Source: AAP
