The United States expects Islamic State (ISIS) to use crude chemical weapons as it tries to repel an Iraqi-led offensive on the city of Mosul, U.S. officials said Tuesday, according to Reuters.
They added, however, that the group's technical ability to develop such weapons is highly limited.
U.S. forces have begun to regularly collect shell fragments to test for possible chemical agents, given Islamic State's use of mustard agent in the months before Monday's launch of the Mosul offensive, one official said.
ISIS is known to have used mustard gas on several occasions in both Syria and Iraq.
In September, the group was suspected of firing a shell containing mustard agent that landed at the Qayarrah air base in Iraq, where American and Iraqi troops are operating. READ MORE