World leaders condemn IS beheading
World leaders have condemned the beheading of US hostage Peter Kassig which featured in a video released by Islamic State.
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.
Footage of his death features a n IS fighter speaking with a London accent and it appears to be the man known as Jihadi John thought to be responsible for previous hostage killings.
The video also shows what IS claims are a group of at least 10 Syrian pilots being murdered by militants.
Prime Minister David Cameron condemned IS as a "depraved organisation" while president Barack Obama said the killing of Mr Kassig was " an act of pure evil".
Mr Kassig's parents said their son died "as a result of his love for the Syrian people".
The American aid worker 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."
Mr Obama praised Mr Kassig as a "humanitarian" who "cared deeply about the plight of the Syrian people".
The president said: "A bdul-Rahman was taken from us in an act of pure evil by a terrorist group that the world rightly associates with inhumanity."
He added: "H is life and deeds stand in stark contrast to everything that ISIL represents. While ISIL revels in the slaughter of innocents, including Muslims, and is bent only on sowing death and destruction, Abdul-Rahman was a humanitarian who worked to save the lives of Syrians injured and dispossessed by the Syrian conflict."
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.
Speaking earlier today before the video emerged, Mr Cameron said 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."
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 British aid workers David Haines and Alan Henning were made public on September 13 and October 3 respectively.
Mr Kassig's p arents, Paula and Ed Kassig, b roke their silence over his captivity last month because "the dynamics" had changed and they feared for his life.
The couple also released excerpts from a letter written by their son in which he feared "it may very well be coming down to the wire here".
They said in a statement tonight: " We are heartbroken to learn that our son, Abdul-Rahman Peter Kassig, has lost his life as a result of his love for the Syrian people and his desire to ease their suffering. Our heart also goes out to the families of the Syrians who lost their lives, along with our son.
"Fed by a strong desire to use his life to save the lives of others, Abdul-Rahman was drawn to the camps that are filled with displaced families and to understaffed hospitals inside Syria. We know he found his home amongst the Syrian people, and he hurt when they were hurting."
They added: "We are incredibly proud of our son for living his life according to his humanitarian calling. We will work every day to keep his legacy alive as best we can."