YouTube
The masked man who appeared in the ISIS video showing a man identified as Alan Henning being beheaded.
The masked man then displays another hostage, who is identified as American aid worker Peter Edward Kassig, and says he will be executed if US-led airstrikes against the group are not stopped.
"Obama, you have started your aerial bombardment ... which keeps on striking our people," the man says. "So, it's only right we continue to strike the next of your people."
The video begins with the man identified as Henning reading a brief statement where he said he was being killed due to the British government's vote last month to join the American airstrike campaign against ISIS. US airstrikes against ISIS were launched in Iraq in August and subsequently expanded to Syria.
Henning was threatened in a previous ISIS video released in September.
Business Insider reached out to the White House's National Security Council to see if they could confirm the authenticity of the video.
ISIS previously released similar videos showing the beheadings of a pair of American journalists and a British aid worker, David Haines. Those videos also featured a masked man with a British accent. Intelligence officials in both the UK and the US reportedly are aware of the identity of the masked man who appeared in the earlier videos.
A Syrian activist who was reportedly imprisoned with Henning told journalist Harald Doornbos that Henning worked for a Muslim NGO.
A spokesperson for the Foreign and Commonwealth Office in Britain sent us this statement:
We are aware of the video and are working urgently to verify the contents. If true, this is a further disgusting murder. We are offering the family every support possible; they ask to be left alone at this time.