Islamic State releases video apparently showing the beheading of missing US journalist James Foley

The White House is attempting to verify footage released by the Islamic State (IS) purporting to show the killing of an American journalist in retaliation for ongoing US airstrikes against its forces in Iraq.

The video circulated on Tuesday showed a masked Isis fighter beheading a kneeling man cloaked in an orange jumpsuit who is purported to be James Foley, a photojournalist who went missing in Syria in 2012. The White House said it was working to establish the video's authenticity, but if it was genuine, the US would be “appalled by the brutal murder”.

Foley has worked in a number of conflict zones in the Middle East, including Syria, Libya and Iraq. He and another journalist were working in the northern province of Idlib in Syria when they were kidnapped in November 2012 near the village of Taftanaz.

The video opened with a clip of US President Barack Obama saying he had authorised strikes in Iraq. “Obama authorises military operations against the Islamic State effectively placing America upon a slippery slope towards a new war front against Muslims,” words appear in English and Arabic on the screen. It showed black and white aerial footage of air strikes with text saying “American aggression against the Islamic State”

A person identified as James Foley and wearing an orange outfit is seen kneeling in the desert as a man in black dress with a black mask stands beside him, holding a knife. “I call on my friends family and loved ones to rise up against my real killers, the US government, for what will happen to me is only a result of their complacency and criminality,” the kneeling man says.

The man in the mask says: “This is James Wright Foley, an American citizen, of your country. As a government, you have been at the forefront of the aggression towards the Islamic State. Today your military air force is attacking us daily in Iraq. Your strikes have caused casualties amongst Muslims. You are no longer fighting an insurgency. We are an Islamic army, and a state that has been accepted by a large number of Muslims worldwide.”

Following his statement he beheads the kneeling man.

The video also shows a second man on his knees, who is named as Steven Sotloff, another American journalist, who was kidnapped in Syria in August 2013. After bringing out Sotloff, the masked executioner addresses the US President directly, saying: “The life of this American citizen, Obama, depends on your next decision.”

The Islamic State had not previously executed American citizens publicly. The video was posted after the United States resumed air strikes in Iraq for the first time since the end of the US occupation in 2011. A Twitter account set up by Mr Foley’s family to help find him said early on Wednesday: “We know that many of you are looking for confirmation or answers. Please be patient until we all have more information, and keep the Foleys in your thoughts and prayers.”