PM in justice vow after latest terrorist hostage is beheaded
Prime Minister David Cameron has condemned Islamic State as a "depraved organisation" after a video was released showing the beheading of US hostage Peter Kassig.
An IS militant speaks with a London accent in the footage and appears to be the man known as Jihadi John who was thought to be responsible for previous hostage killings.
Mr Kassig was captured by IS fighters - also known as Isil- in Syria in October last year while providing medical training and humanitarian aid to victims of the country's conflict.
He was born Peter but changed his name to Abdul-Rahman following his conversion to Islam while in captivity.
Mr Cameron said: "These beheadings show once again what a depraved organisation this is.
"Like others who have been murdered in cold blood by Isil, Abdul-Rahman Kassig was a selfless humanitarian worker who had gone to the region to help care for those fleeing the Syrian conflict.
"This underlines the deplorable depths to which these terrorists are prepared to go - savagely murdering a compassionate man."
The Prime Minister said his "heart goes out" to Mr Kassig's family.
Previous beheading videos showed a desert landscape, but in this latest release the IS militant appears to be standing in front of a town with fields in the distance.
Mr Kassig's severed head is shown at the feet of a militant wearing black trousers and military-style khaki boots.
The latest video also shows what IS claims are a group of at least 10 Syrian pilots being murdered by militants.
Mr Kassig's parents Paula and Ed asked for their son to be "remembered for his important work and the love he shared with friends and family".
Mr Cameron said earlier that he wants Jihadi John to face justice, after reports that he was injured in an allied air strike against IS commanders in Iraq.
The masked fanatic, believed to be responsible for the beheading of two British and two American hostages, is reported to have been taken to hospital after narrowly escaping death in the raid.
The Prime Minister said: ''You should be in no doubt that I want Jihadi John to face justice for the appalling acts that have been carried out in Syria, but I wouldn't make any comment on individual issues and strikes."
Labour leader Ed Miliband said: "My deepest sympathies go to the family of Abdul-Rahman Kassig today. These brutal killers must face justice.
"I am sickened by the senseless murder of a man who had dedicated his life to helping others."
Former prime minister Sir John Major described Mr Kassig's murder as "13th-century barbarism".
He told BBC1's The Andrew Marr Show yesterday: "The people they are murdering, which makes it doubly worse, triply worse, are people who actually went there to help those in difficulty and in need.
"They are being murdered in the most brutal ways, almost beyond belief."
Mr Kassig's parents said: "We are aware of the news reports being circulated about our treasured son and are waiting for confirmation from the government as to the authenticity of these reports. We will have no other statement at this time and ask that you please respect our privacy."
The latest video is the fifth time this year that IS has published footage showing the murder of Western hostages. The beheading of James Foley was released online on August 19 and the killing of fellow US journalist Steven Sotloff was broadcast on September 2. Footage of the murders of UK aid workers David Haines and Alan Henning were made public in September and October.