ISIS video purports to show beheading of British aid worker

The Islamic State in Iraq and Syria (ISIS) released a video late Saturday that appears to show the beheading of British aid worker David Haines, who went missing in Syria last year.

{mosads}The British Foreign Office said it was “working urgently to verify” the authenticity of the video, which surfaced hours after the family of Haines issued a public plea urging his captors to contact them, according to The Associated Press.

President Obama issued a statement condemning “the barbaric murder” of Haines by the Islamic State terrorist group.

“The United States stands shoulder to shoulder tonight with our close friend and ally in grief and resolve. We will work with the United Kingdom and a broad coalition of nations from the region and around the world to bring the perpetrators of this outrageous act to justice, and to degrade and destroy this threat to the people of our countries, the region and the world,” Obama said. 

The ISIS video post showing Haines’s purported beheading called his execution “A message to the allies of America” and showed a masked militant telling the British government that its alliance with the U.S. will only “accelerate your destruction” and will drag the British people into “another bloody and unwinnable war.”

The SITE Intelligence Group, a U.S. terrorism watchdog, reported the nearly three-minute video.

If confirmed, Haines would be the third western hostage beheaded by the radical Islamist group in recent weeks, following the brutal killing of American journalists James Foley and Steven Sotloff, also posted online.

In a tweet, Britain Prime Minister David Cameron called “the murder of David Haines” an “act of pure evil.”

He added, “We will do everything in our power to hunt down these murderers and ensure they face justice, however long it takes.”

Haines, 44, a father of two, was captured by Islamic State in Syria in March 2013 while working for an international aid agency.

This post was updated at 10:00 p.m.