The U.S. has targeted British Islamic State leader Mohammed Emwazi, aka "Jihadi John," in an airstrike in northern Syria, the Pentagon said Thursday.

Reuters reports the Pentagon has not yet confirmed whether Emwazi was taken out in the strike or not. However, they are "reasonably certain" the infamous terrorist perished.

A U.S. official said Emwazi was "probably" killed in the attack, conducted in the Syrian city of Raqqa, considered to be the de facto capital of ISIS.

"A car carrying four foreign Islamic State leaders, including one British Jihadi was hit by U.S. air strikes right after the governorate building in Raqqa city," said Rami Abdulrahman, director of the Syrian Observatory for Human Rights, a U.K.-based monitoring group.

The organization also cited sources as saying Emwazi was "blown to pieces" by the air strike. NBC News reports one of the three MQ-9 Reaper drones keeping tabs on Emwazi fired after allegedly spotting him and another man exit a building an enter a car.

Emwazi was the most prominent British member of the ISIS terrorist group. The black-masked militant appeared in a number of videos in 2014 and 2015, in which he murdered several hostages.

His most notable victims included U.S. journalists Steven Sotloff and James Foley, U.S. aid worker Abdul-Rahman Kassig, British aid workers David Haines and Alan Henning, and Japanese journalist Kenji Goto.

British Prime Minister David Cameron said that Emwazi "posed an ongoing and serious threat to innocent civilians, not only in Syria but around the world and in the United Kingdom too."

Cameron added that the U.S. strike was carried out with the cooperation of the U.K. He added, "It was the right thing to do."

Born in Kuwait, Emwazi was raised in West London, where he eventually attended the University of Westminster and obtained a degree in computer programming.

As a young man in his 20s, Emwazi became involved in a network of young Muslims referred to as The North London Boys, who recruited potential terrorists to fight in Somalia and Syria.

According to a source at The New York Times, the group was "a network of United Kingdom and East African-based Islamist extremists involved in the provision of funds and equipment to Somalia for terrorism-related purposes."