ISIS video claims beheading of US hostage Peter Kassig

ISIS militants have allegedly beheaded US aid worker Peter Kassig; a video posted on social media shows.

The video – which has been circulated online through credible social media accounts that have previously shares similar videos – also shows ISIS members behead several Syrian soldiers who were allegedly pilots and officers in Syria President Bashar al-Assad’s military.

The authenticity of the footage is yet to be verified.

The footage reportedly shows Jihadi John murdering Kassig. This comes despite earlier reports that the extremist, who has executed other UK and US hostages, was wounded in an airstrike on a top-level extremists’ meeting in Iraq last week.

If the death is confirmed, Kassig will be the fifth Westerner to be executed by ISIS militants.

Kassig, 26, was captured on October 1, 2013, by Islamic State) militants on his way to the city of Deir Ezzour in eastern Syria.

After converting to Islam during captivity, Kassig took the name Abdul-Rahman.

In the video the extremists deliver warnings to the US, UK and other countries.

In a highly choreographed sequence in the video, the self-declared jihadists marched at least a dozen prisoners said to be Syrian officers and pilots past a wooden box containing long military knives, each ISIL member taking one as they passed.

They then forced the men to kneel in a line and decapitated them.

Two American journalists and two British aid workers had already been beheaded by ISIL in what the group says are retaliatory killings for the US-led air campaign against its fighters in Iraq and Syria. 

Islamic State militants first showed Kassig in the video of the beheading of UK aid worker Alan Henning, who shared a prison cell with Kassig. After Jihadi John, an IS executioner with a London accent, killed Henning, he also threatened Kassig would be next.

In the meantime, the UK Foreign Office said it is examining the video’s authenticity.

"We are aware of a further video and are analyzing its contents. If true, this is a further disgusting murder," a spokeswoman told Reuters.

The White House said the US intelligence community was working to determine the authenticity of the video.

If the video is authentic, the White House would be "appalled by the brutal murder of an innocent American," National Security Council spokeswoman, Bernadette Meehan, said.