Transcript for Battle for Mosul, Iraq, leaves civilians on the run

humanitarian crisis in Iraq. Thousands of civilians are fleeing mosul. Some may have been exposed to chemical weapons. The united nations warning against war crimes. ABC's Jennifer Eccleston reports from London. Reporter: They're fleeing the last strong hold in Iraq. The escape so hasty, many residents leaving without shoes. Iraqi forces and civilians facing a fierce pushback from ISIS, who have controlled the city for nearly three years. Now evidence of a possible chemical weapons attack. A Robert landed on our house, this mother says. It exploded and sprayed us with oily terrible. She and her children, and seven other patients here showing signs of gas poisoning. An emergency response planned is now in effect. Some people have breathing problems like a spasm, like in an asthma attack. And the majority of the patients have developed different size of blisters. Reporter: The battle has raged for five months. The Iraqis are taking back the city. Workers with preemptive love paint a dire picture. The hardest thing that we're seeing right now across this conflict is hundreds of thousands of people desieged by ISIS starving to death. Reporter: Thousands more remain trapped behind ISIS lines, waiting for any chance to escape. Jennifer Eccleston, ABC news, London. The goebl community wanting to know now help. Humanitarian organizations are operating completely independently, autonomously from the U.N. Going where the U.N. Can't reach at this point. Completely funded by private citizens, civilians like you and I. They're the first humanitarian group to reach that location. ISIS doing everything they can to hold on. We can see it. These families dealing with chemical attacks. War. Mother nature with the mud and rain. It's incredible. Organizations are needed. They're doing the brave work so few of us are willing to do. So kudos to them.

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