The UN's refugee agency has warned that thousands of people are still trapped in Syria's economic hub, Aleppo, as the army offensive against rebel strongholds continued for a fourth day.
Activists in the city say supplies of food and cooking gas are running low.
Fresh clashes and attacks by helicopter gunships have been reported, but rebels say they have held on to the key district of Salah al-Din.
The UN says 200,000 people have fled the fighting in the city.
But Melissa Fleming, a spokeswoman for the UNHCR refugee agency, said many more had been unable to leave because they did not have the means to make the journey, or felt it would be too dangerous.
An estimated 15,000-16,600 frightened residents have sought refuge in schools, mosques and public buildings in the city, she said.