The US has said so-called "Islamic State" (IS) fighters are using human shields and could use chemical weapons as the Mosul offensive continues. Mosul represents the last stand of IS in Iraq.
Fighters with the so-called "Islamic State" (IS) group have been trapping Mosul's civilian population to use as human shields, the Pentagon said on Tuesday.
Pentagon spokesman Navy Captain Jeff Davis said IS had for weeks prevented Mosul's estimated population of 1.5 million from escaping.
"We know they are being used as human shields, absolutely," Davis told reporters. "They are being held there against their will. We have not seen any change in the last day of people leaving or fleeing."
The International Organization for Migration's (IOM) Iraq chief, Thomas Weiss, said he also expected IS to use Mosul residents as human shields. "We also fear, and there has been some evidence that ISIL [IS] might be using chemical weapons. Children, the elderly, disabled, will be particularly vulnerable," he added.
US President Barack Obama said on Tuesday that "plans and infrastructure" were in place for dealing with a potential humanitarian crisis should thousands flee the city. The UN has been working on the assumption that as many as 200,000 people might need shelter as the military operation develops.
Chemical weapons feared
US forces said they were collecting shell fragments to test for possible chemical agents. They confirmed the presence of a sulfur mustard agent on IS munition fragments used in an attack on local forces on October 5. Sulfur mustard agents can cause blistering on exposed skin and lungs.
"Given ISIL's reprehensible behavior and flagrant disregard for international standards and norms, this event is not surprising," a US official told Reuters, speaking on condition of anonymity, and using an acronym for IS.
However, US officials said they doubted the ability of the jihadist fighters to develop chemical weapons with particularly lethal effects.
Mosul offensive on two fronts
After the second day of the offensive, Iraqi commanders said progress was being made as fighters pushed on two main fronts against the jihadists' last stronghold in Iraq.
The long-awaited offensive on Iraq's second-largest city was launched on Monday, with 30,000 federal forces leading Iraq's largest military operation since the 2011 pullout of US troops. Iraqi troops are moving in from the south while Kurdish fighters are approaching from the east.
About 700,000 people are believed to still be in Mosul. There are an estimated 5,000 IS fighters still in the city.
The US-backed coalition claims to have driven IS out of 10 villages in the surrounding area.
Obama said on Tuesday night that the military operation to reclaim Mosul would be a "difficult fight" but that driving the IS fighters from Iraq's second-largest city "will be another step toward their ultimate destruction."
jbh/jm,jr (Reuters, AFP)