Islamic State confirmed to have used mustard gas against Kurds in Syria

The Islamic State in Iraq and the Levant (Isil) used mustard agent in its fight against a Kurdish militia in Syria, testing has confirmed.

Unnamed US government officials involved in investigating alleged chemical weapon use by Isil in the northeastern Syrian city of Hasakeh confirmed mustard gas had been used, according to the Washington Post and CNN.

Mustard gas, used during World War One, can cause blisters, blindness and respiratory damage and is an internationally-banned chemical weapon.