An Internet video posted online Tuesday purported to show the beheading of U.S. journalist Steven Sotloff by the Islamic State group, which called it retribution for continued U.S. airstrikes in Iraq.

Sotloff, 31, who freelanced for Time and Foreign Policy magazines, had last been seen in Syrian in August 2013 until he appeared in a video released online last month by the Islamic State group that showed the beheading of fellow American journalist James Foley.

Dressed in an orange jumpsuit against the backdrop of an arid Syrian landscape, Sotloff was threatened in that video with death unless the U.S. stopped airstrikes on the group in Iraq.

In the video distributed Tuesday and entitled "A Second Message to America," Sotloff appears in a similar jumpsuit before he was purportedly beheaded by an Islamic State fighter.

The Associated Press could not immediately verify the video's authenticity. The SITE Intelligence Group, a U.S. terrorism watchdog, first reported about the video's existence.

The fighter who beheads Sotloff in the video called it retribution for Obama's continued airstrikes against the group in Iraq.

"I'm back, Obama, and I'm back because of your arrogant foreign policy towards the Islamic State ... despite our serious warnings," the fighter said.

At the end of the video, he threatened to kill a third captive, a Briton, David Cathorne Haines.

Read more at KFI News