We’ll hunt down the monsters who killed aid hero

The Prime Minister hailed Yorkshire-born David Haines as a “British hero” and vowed to “hunt down those responsible and bring them to justice no matter how long it takes” after “Islamic State” (IS) posted a video of the beheading of the father-of-two.

The hostage’s brother Mike Haines paid tribute to him yesterday and warned IS posed a threat to “every nation, every religion, every politics and every person”.

The video also showed a second British hostage, named as Alan Henning, with a threat that he would be the next to be killed.

The beheading appeared to have been carried out by the same British-accented jihadist responsible for the deaths of two American journalists held by the group - which is also known as Isil (Islamic State of Iraq and the Levant). In a statement released by the Foreign Office, Mike Haines said: “Our brother, son, father, nephew, husband and friend was brutally and cold-bloodedly murdered by Isil after being held hostage since March 2013.”

The statement praised the Foreign Office, police and other the agencies for the support and co-operation Mr Haines’s family had been given in their time of need.

It also said the family agreed with the Government about the threat posed by IS.

It added: “Radicalisation remains the biggest threat to the wholesale safety of every person in the world.”

After chairing a meeting of the Government’s Cobra emergency committee, the Prime Minister said the brutal crime would “strengthen our resolve” to take on the threat posed by the Islamic extremists at home and abroad.

British people would be “sickened” that a fellow citizen could have carried out such an act, the Prime Minister said and urged action to drain from society the “poison” of radicalisation – insisting IS and its adherents “are not Muslims, they are monsters”.

He remained tight-lipped on Britain’s role in the planned escalation of the military offensive in Iraq and Syria being co-ordinated by the US, and officials said there were no immediate plans to recall Parliament to discuss use of British Armed Forces.

He ruled out sending ground troops, but left the door open to air strikes. Fears for Mr Haines’s life had intensified when he was paraded as the next intended victim in the video of the death of journalist Steven Sotloff and Mr Cameron paid tribute to the “extraordinary courage” shown by the Haines family since he was taken in Syria in March last year.

“The whole country, like his grieving family, can be incredibly proud of what he did and what he stood for in his humanitarian mission,” he said. US president Barack Obama said the US, where the two previously murdered hostages were from, “stands shoulder to shoulder with our close friend and ally in grief and resolve”.