CNN reports that “the military assesses that the shell fired on a joint US-Iraqi base Tuesday was indeed a chemical weapon, according to Chairman of the Joint Chiefs of Staff Gen. Joseph Dunford.”

“We assess it to be a sulfur mustard blister agent,” Dunford told the Senate Armed Services Committee Thursday. It is the first time the military has confirmed its assessment on the record since CNN reported the development Wednesday.”

“A US military official told CNN, however, that the first field test for chemical agent was positive and the second test was negative. The substance was sent to a coalition-operated Iraq-based lab, and tests there were inconclusive. The official said the sample will now be sent to another lab for additional testing.”