WASHINGTON (CBSNewYork/CBS News/AP) -- ISIS, the Islamic extremist group that has overrun parts of Syria and Iraq, released a video Tuesday that apparently shows the beheading of American journalist James Foley.
The militant group also threatened to kill another U.S. journalist if the U.S. does not halt its airstrikes in Iraq, CBS News reported
The group – known in full as the Islamic State of Iraq and Syria -- released a video titled "A Message to America" that appeared on several social media websites. YouTube removed the video shortly after it was posted, CBS News reported.
The video shows a militant using a knife to decapitate a man the group identifies as Foley, CBS News reported. The 40-year-old freelance journalist who had been based in Boston disappeared in northwest Syria on Thanksgiving Day, Nov. 22, 2012.
At the end of the video, a second hostage is seen. He is identified in the video as freelance photojournalist Steven Joel Sotloff of Miami.
An ISIS extremist said Sotloff will be the next to die if the United States does not stop its attacks on ISIS positions in northern Iraq. CBS News has not confirmed the identity of the second man.
Two U.S. officials said Tuesday they believe Foley was the person executed by Islamic State militants in a video posted online. The officials spoke on the condition of anonymity because they weren't authorized to discuss the video by name.
But the Obama administration said Tuesday night that it had not determined whether the video is authentic, CBS News reported.
"We have seen a video that purports to be the murder of U.S. citizen James Foley," National Security Council spokeswoman Caitlin Hayden said in a statement. "The intelligence community is working as quickly as possible to determine its authenticity. If genuine, we are appalled by the brutal murder of an innocent American journalist and we express our deepest condolences to his family and friends. We will provide more information when it is available."
The New York-based Committee to Protect Journalists said about 20 journalists are missing in Syria.
CPJ has not released the nationalities of the other missing journalists.
In its annual report last November, CPJ concluded that the missing journalists are either being held and threatened with death by extremists, or taken captive by gangs seeking ransom. The group's report described the widespread seizure of journalists as unprecedented and largely unreported by news organizations in the hope that keeping the kidnappings out of public view may help in the captives' release.
Foley's father had made a plea for his son's safe return.
"We're gravely concerned about Jimmy's health and welfare and safety," he said.
By Tuesday night, the following statement had appeared on Facebook:
"We have never been prouder of our son Jim. He gave his life trying to expose the world to the suffering of the Syrian people. We implore the kidnappers to spare the lives of the remaining hostages. Like Jim, they are innocents."
In 2002, American journalist Daniel Pearl was kidnapped by militants in Pakistan and later beheaded by al Qaeda member Khalid Sheikh Mohammed, who is now in U.S. custody, CBS News reported.
Foley was on assignment for Agence France-Press and the Boston-based media company GlobalPost when he disappeared in Syria in 2012.
Philip Balboni, GlobalPost chief executive officer and co-founder, said the company was waiting for the administration's evaluation of the video, but said Foley's parents were grateful for the public's support and prayers.
"On behalf of John and Diane Foley, and also GlobalPost, we deeply appreciate all of the messages of sympathy and support that have poured in since the news of Jim's possible execution first broke," Balboni said in a statement. "We ask for your prayers for Jim and his family."
The oldest of five children, Foley grew up in New Hampshire and studied history at Marquette University. He was a teacher before switching careers to journalism. He had worked as a journalist in the Middle East for five years when he was kidnapped in Syria.
As CBS 2's Jessica Schneider reported, Foley had a passion for telling stories from war torn nations. He had been taken captive once before. In 2011, he was taken prisoner by forces loyal to Libyan dictator Moammar Gadhafi and held for more than 40 days before being released.
He appeared on the old CBS Early Show in 2011 after being released from captivity there.
"We were going out to report on what was actually happening on the front lines. It's very important in this kind of war to see if what the rebels are saying they're doing is actually true, so it's important to go out there and confirm, and go back to report to our agencies. That day, we hitched a ride up to the front lines, and we were told that Qaddafi forces were very close," Foley said in 2011.
He described being kidnapped while on that mission -- seeing an AK-47 displayed, being punched, and dragged into a vehicle with his hands behind his back.
Sotloff, said to be the man whose life ISIS threatens at the end of the video, disappeared in July 2013 while reporting in northern Syria. His work has appeared in Time magazine and Foreign Policy. The freelance journalist had reported from Libya and Yemen in addition to Syria.
Among the other journalists missing in Syria is American Austin Tice. His family says the freelance journalist was taken captive near Damascus, Syria, on Aug. 14, 2012.
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