US president Barack Obama has said the beheading of Peter Kassig by the Islamic State group in Syria is “an act of pure evil”.

The parents of an American aid worker captured last year while delivering relief supplies to refugees in Syria said they are “heartbroken” by his death at the hands of Islamic State militants.

A Pentagon probe will recommend that nine officers, including up to four generals, be held accountable for mistakes in the aftermath of the friendly-fire death of a former US football star killed by his comrades in Afghanistan.

Five US Army soldiers have been charged with abusing detainees in Iraq, the US military said today.