Video appears to show US aid worker Peter Kassig killed by Islamic State

A new video has been posted online which appears to show US aid worker Peter Kassig being killed by Islamic State militants.

Kassig, 26, was taken hostage in Syria in October 2013 and threatened at the end of another video last month which showed the murder of British aid worker Alan Henning.

Today's video features a message in which a masked figure with a British accent announces the killing of Mr Kassig before criticising Barack Obama's foreign policy.

He then issues a threat to US troops but does not name specific targets for future murders, as in previous videos.

Kassig had been a soldier with US special forces and served briefly in Iraq before retraining as a medical technician and heading to Syria.

He converted to Islam last year and went by the name Abdul-Rahman Kassig.

Just yesterday a Twitter account in the Kassig family's name issued a new appeal for his release.

Last month his family released portions of a moving letter he sent to them from captivity.

ITV News UK Editor Rohit Kachroo said the video of Mr Kassig's killing showed the location of the murder for the first time.

It also featured another section which showed the mass killing of a number of other hostages, all by knife-wielding IS militants.

At just over 15 minutes long, parts of the video were shot in high definition and used high-quality sound and video editing.