The ISIS terror group has released a graphic new video which they claim shows the beheading of American hostage Peter Kassig.

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Fox News chief intelligence correspondent Catherine Herridge reported on "Fox News Sunday" that the 16-minute video is being reviewed by the U.S. intelligence community to determine its authenticity.

She noted that to date, ISIS has not made a false claim about the execution of hostages.

If confirmed, Kassig will be the fifth Western hostage beheaded by the terror group - and the third American - in less than three months, Herridge said, adding that Kassig, a former Army Ranger, went to the Middle East to work as a medical assistant.

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"The new video is a dramatic departure from previous propaganda tapes and includes what appears to be the mass beheading of more than a dozen members of the Syrian military," Herridge said.

She revealed there are at least two sections of the video that purport to feature the British executioner 'Jihadi Johnny.'

"Analysts say the tape may provide new clues about the group's location, especially its leadership, with unconfirmed reports the British executioner was injured in last weekend's airstrikes," Herridge said.

On the president's strategy in Iraq and Syria, Herridge noted that yesterday Obama's former defense secretary Robert Gates criticized the president as "micromanaging" the military, meddling in a way that has not been seen since Vietnam.

Watch Herridge's report above and see Amb. John Bolton and Col. Ralph Peters react below.

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