ISIL targeting people who try to flee
Meanwhile, people who stay are without food and water. No steady supplies have been able to reach the city since mid-November, Ms. Grande said.
Families with resources are trying to trade what they can to eat even one meal a day, according to stories from people who were able to flee, while some people go for days without meals.
Hoping to limit civilian casualties
Those who do flee are screened at the Hammam al Alil site, with the men separated from the women and children. Once interrogated and cleared, the families are reunited.
Ms. Grande said that there are concerns about water and sanitation at the screening sites, and that the Government has asked for additional support to help it correct those conditions.
The UN and its partners are supplying food, water and other services to the sites, with more than 1.4 million people reached.
