Footage released late Friday showed the murder of the 47-year-old aid convoy volunteer. Henning was a Manchester taxi driver who travelled to Syria to help distribute food and clothing to stricken civilians, reported Xinhua citing The Times Saturday.
Delivering the message via his twitter account, Cameron said: “I’m meeting security chiefs this morning to discuss the barbaric murder of Alan Henning. His killers will be hunted down and face justice. His killers will be hunted down and face justice.”
The IS has previously released videos showing the apparent beheading of two U.S. journalists, James Foley and Steven Sotloff, as well as British aid worker David Haines.
In the latest footage, similar to the previous ones, Peter Kassig, a US aid worker, was paraded at the end of video.