The Latest: UN prepares for chemical attacks in Iraq's Mosul

Iraqi army soldiers rest at a checkpoint in Qayara, some 50 kilometers south of Mosul, Iraq, Wednesday, Oct. 26, 2016. Islamic State militants have been going door to door in farming communities south of Mosul, ordering people at gunpoint to follow them north into the city and apparently using them as human shields as they retreat from Iraqi forces. Witnesses to the forced evacuation describe scenes of chaos as hundreds of people were driven north across the Ninevah plains and into the heavily-fortified city, where the extremists are believed to be preparing for a climactic showdown. (AP Photo/Marko Drobnjakovic) (The Associated Press)

Iraqi army soldiers rest at a checkpoint in Qayara, some 50 kilometers south of Mosul, Iraq, Wednesday, Oct. 26, 2016. Islamic State militants have been going door to door in farming communities south of Mosul, ordering people at gunpoint to follow them north into the city and apparently using them as human shields as they retreat from Iraqi forces. Witnesses to the forced evacuation describe scenes of chaos as hundreds of people were driven north across the Ninevah plains and into the heavily-fortified city, where the extremists are believed to be preparing for a climactic showdown. (AP Photo/Marko Drobnjakovic) (The Associated Press)

The Latest on the conflict in Iraq (all times local):

12:30 p.m.

The U.N.'s public health agency says it has trained 90 Iraqi medics in "mass casualty management" as part of its preparations for the Mosul offensive, with a special focus on responding to chemical attacks.

The Islamic State group, which has ruled Iraq's second largest city for more than two years, is believed to have crude chemical weapon capabilities.

The World Health Organization said Wednesday that of the 700,000 people expected to flee Mosul, some 200,000 will require emergency health services, including more than 90,000 children needing vaccinations and 8,000 pregnant women.

The operation to retake Mosul began Oct. 17 and is expected to take weeks, if not months. The International Organization for Migration says around 9,000 people have fled. The fighting has not yet reached the city itself, which is home to more than a million people.

___

11:45 a.m.

The United Nations' refugee agency is shipping tents, blankets and other aid from the United Arab Emirates to northern Iraq to help those affected by the military campaign to retake Mosul from the Islamic State group.

The UNHCR shipment, leaving Dubai's International Humanitarian City on Thursday, is expected to reach those affected as soon as Friday.

Soliman Mohamed Daud, a senior UNHCR supply officer, told The Associated Press that 7,000 units of the relief aid will be sent to northern Iraq. The UAE shipment leaving Thursday includes some 1,500 kits.

Iraqi and Kurdish forces, backed by U.S. advisers and airstrikes, began the operation to retake Iraq's second-largest city earlier this month.

Aid groups fear that a mass exodus from Mosul could overwhelm camps set up around its outskirts.