(VOVworld) - A video has been released on the internet that purports to show an Islamic State fighter beheading British hostage Alan Henning, the fourth such killing carried out by the armed group now being targeted by US-led air strikes.

British hostage Alan Henning (Photo: AFP)

The Salford taxi driver was delivering aid to Syria in December when he was kidnapped and then held hostage by IS. IS threatened to kill him in footage last month showing the death of Briton David Haines, and in this video they threaten US aid worker Peter Kassig. David Cameron said Britain would do all it could "to hunt down these murderers and bring them to justice". The prime minister said the killing of father-of-two Mr Henning, 47, showed "how barbaric and repulsive" IS was.

On the same day, US President Barack Obama criticized the beheading, saying that the US will bring the perpetrators to justice. French President Francois Hollande expressed his anger on this and said France will support Iraq’s government and people in the fight against terrorism.

The Netherlands and Canada have considered to sending more aircraft to the air strikes targeted the IS in Iraq.