The UN children's agency UNICEF estimates that around 60 percent of those displaced -- around 19,000 -- are children
The UN said some 31,500 people had fled their homes in opposition-held east Aleppo since November 24, when the Syrian government intensified its brutal offensive to retake the entire city.
The UN children's agency UNICEF estimates that around 60 percent of those displaced -- around 19,000 -- are children.
The number of displaced children could be far higher: the Syrian Observatory for Human Rights puts the overall number of people on the run from the violence in east Aleppo at more than 50,000 since Saturday.
"What is critical now is that we provide the immediate and sustained assistance that these children and their families desperately need," UNICEF spokesman Christophe Boulierac told reporters in Geneva.
"It's a race against time, as winter is here and conditions are basic," he added.
He said UNICEF had "winter clothing and blankets ... ready for distribution (to) at least help to provide some protection from the freezing temperatures."
The UN refugee agency meanwhile warned Friday that the main focus now in providing aid to those flooding out of east Aleppo is "the rapidly growing shelter needs".
"Many of those who have fled eastern districts are now in unfinished or partly destroyed buildings," UNHCR spokesman Adrian Edwards told reporters.
"Unsanitary conditions and overcrowding are already challenges in a congested city with few open spaces," he said, pointing out that even before the latest exodus from east Aleppo there were already some 400,000 displaced people in the government-held west of the city.
In addition to trying to provide shelter, food, healthcare and other physical assistance to the displaced, the UN is also providing much needed psychological support, he said.
That is vital, according to Boulierac, who said UNICEF staff meeting with children who have fled east Aleppo in recent days said "you could see the loss and horror in their eyes."
He said UNICEF was also rushing to provide vaccinations for the newly displaced children, pointing out that "many children in east Aleppo have missed out on critical routine vaccinations to protect them from preventable childhood illnesses."
The UN is meanwhile desperately trying to gain access to the people who remain inside east Aleppo where more than 300 civilians, including dozens of children, have been killed since the government launched its offensive on November 15, according to the Observatory.
The escalation of violence in Aleppo has been met with international outrage, including a warning by the UN that the city's east could become "a giant graveyard".