ISIS militants were making rudimentary chemical weapons at the University of Mosul, the US Department of Defense spokesperson Jeff Davis said.
The Iraqis have run tests on the chemicals and these proved positive for sulphur mustard, Davis said, adding that Mosul university was "central to the ISIS chemical weapons program".
"It was used primarily as an irritant and something to scare people," he noted.
On February 1, Operation Inherent Resolve spokesman Col. John Dorrian said that ISIS has used Mosul University for chemical weapons production.
