Baghdad, June 1 (RHC)-- UNICEF, the United Nations Children's Fund, warns that 20,000 children are trapped in the fierce battle between Iraqi forces and the Islamic State in Fallujah, where food, water and medicine is running out.

Peter Hawkins, UNICEF Representative in Iraq, said in a statement that the UN agency is "concerned over the protection of children in the face of extreme and rising danger."

Hawkins said UNICEF urges the warring factions to protect children and civilians in Fallujah and to provide safe passage to families who want to leave the city. 

The Islamic State has reportedly killed civilians as they attempted to flee the city.  Fleeing families have reported the Islamic State has used civilian hostages as human shields.

About 625 families reportedly escaped the Fallujah fighting in the past week and nearly 500 men and boys over the age of 12 have been held for security screenings.  The United Nations previously estimated about 10,000 families were trapped inside the Syrian city.