Notorious terrorist Mohammed Emwazi, known by his nickname "Jihadi John," is reported to have been killed in an airstrike in Syria on Thursday, with U.S. officials stating that the ISIS executioner was "eviscerated" in a drone attack as he left a building in Raqqa, according to The Telegraph.

Though the certainty of the terrorist's death has not yet been announced, a senior military official has stated that there is a "high degree of certainty" that Jihadi John has been killed. Another source has also stated that the U.S. is 99 percent sure that that attack was successful, reports The Wall Street Journal.

The Pentagon, however, has only stated that it was "confident" that the air strike was a success.

Emwazi, a Kuwaiti-born British militant, managed to gain worldwide notoriety after being featured in a number of ISIS' propaganda videos. Believed to have joined the Islamic State after travelling to Syria in 2013, he appeared in a video in August of last year which featured the death of U.S. journalist James Foley, according to BBC News.

He was also pictured during beheadings of U.S. journalist Steven Sotloff, American aid worker Abdul-Rahman Kassig, British aid worker David Haines, U.K. taxi driver Alan Henning and Japanese journalist Kenji Goto. In each of the videos, Emwazi was seen wearing a black robe with a black balaclava covering his face.

If the attack was indeed successful, the strike would be a substantial symbolic victory in the fight against the Islamic State.

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