Turnabout: ISIS Fighter Makes July 4 Threat, Reportedly Killed That Day

ISIS-associated Twitter accounts mourn reported "martyrdom" of Brit extremist.

U.S. officials declined to confirm or deny Aziz’s death, and extremists have faked death online before. A representative for the British Home Office said that in general, the office does not comment on individual cases.

Anjem Choudary, a controversial London-based Islamic figure and former associate of Aziz, told ABC News he understood Aziz’s death to be confirmed and asked that “Allah accept him in paradise.”

Aziz was prolific in ISIS’s social media outreach, allegedly luring recruits and inspiring attacks on the West online from a number of Twitter accounts.

“America likes hitting people,” said a Twitter account attributed to Aziz recently, “but doesn’t like getting hit back… Oh well, every action has a reaction.”

“Obviously he is a person, definitely of interest to authorities because of the influence that he has online and the fact that he has been in contact with people in the West ready to carry out attacks,” Vidino said. “He was one of the key people inciting attacks in the West, calling people in the West through social media to carry out attacks.”

Late today President Obama announced the U.S. is taking off the gloves when it comes to hitting ISIS targets in Syria.

“We’re going after ISIL [ISIS] leadership and infrastructure in Syria, the heart of [ISIS] that pumps funds and propaganda to people around the world,” he said.

The President cited the attack on a Mohammed cartoon contest in Texas in May as the sort of threat the U.S. now faces. The men behind that attack were inspired by Aziz, among others.

The Telegraph reported Aziz traveled to Syria after he was convicted of stabbing a soccer fan in the eye in London. Vidino said that before he left, Aziz was a known member of the “radical scene” in the U.K.