Islamic State Beheads Peter Kassig, Obama Calls Execution ‘An Act Of Pure Evil’

The Islamic State group released a video Sunday showing a masked militant standing over the severed heads of a dozen Syrian soldiers, as well as that of Peter Kassig, a 26-year-old former United States Army Ranger-turned-aid worker, the Associated Press reported.

Kassig, who founded an aid group to help Syrians caught in the war, was seized in October of the previous year while he was delivering relief supplies in eastern Syria, the AP report added.

"We say to you, Obama: you claim to have withdrawn from Iraq four years ago," the masked militant in the video said, as quoted by AP. "Here you are. You have not withdrawn. Rather, you hid some of your forces behind your proxies."

U.S. President Barack Obama confirmed Kassig's identity in the video and condemned the extremist group for reveling in the slaughter of innocents, calling it "an act of pure evil by a terrorist group that the world rightly associated with inhumanity."

The video was confirmed to have been taken at Dabiq, a town in northern Syria that the IS group uses as the title of its propaganda magazine, the AP report noted.

With Kassig's death, the IS group has now killed five Westerners, including American journalists James Foley and Steven Sotloff and British aid workers David Haines and Alan Henning, according to the Associated Press.

Unlike in Kassig's video, the militant's clips of the past Westerners had them kneeling in orange jumpsuits and were forced to make a speech before being beheaded, stated the AP report. The IS group is still holding John Cantlie, a British photojournalist, and a 26-year-old American woman who worked for the aid groups.

British Prime Minister David Cameron said he was horrified over the cold-blooded murder of Kassig, condemning the IS group for their depraved actions, reported AP.

Burhan Agha, who worked with Kassig, released a statement via a telephone call to the Associated Press while staying in Switzerland where he was seeking asylum.

"If I could apologize to each American, one by one, I would, because Peter died in Syria, while he was helping the Syrian people," Agha said, weeping during the call. "Those who killed him claimed to have done it in the name of Islam. I am a Muslim and am from Syria. His killers are not Muslims."

"This is an act of desperation," said Frank Gardner the security correspondent for BBC.

"Mr Kassig's murder is a sign of frustration that IS militants are unable to hit back at the coalition air strikes that have driven them off key sites like the Mosul and Haditha dams, and prevented them from seizing the town of Kobane," Gardner wrote in the BBC report.

Kassig's parents, Ed and Paula Kassig, released a statement, saying they were "heartbroken" but "incredibly proud" of their son's humanitarian work, reported AP. They said their son "lost his life as a result of his love for the Syrian people and his desire to ease their suffering."

The couple also released excerpts from their son's letters to them, as mentioned in the BBC report.

"They tell us you have abandoned us and/or don't care, but of course we know you are doing everything you can and more," Kassig wrote in the letter, per BBC. "Don't worry, Dad. If I do go down, I won't go thinking anything but what I know to be true, that you and Mom love me more than the moon and the stars."