Orlando terror attack gunman Omar Mateen called 911 just before the shooting to pledge his allegiance to the ISIS leader Abu Bakr al-Baghdadi, NBC News reports.

He also mentioned the Tsarnaev brothers, who carried out the Boston Marathon bombing, during the call, CBS News reports.

Mateen killed 49 people and wounded more than 50 others in the assault on the Pulse nightclub, one of Orlando’s largest gay clubs. The shooting is the worst mass killing in American history.

ISIS has not officially taken credit for the attack, and officials have indicated it is more likely to have been an ISIS-inspired attack, like the San Bernardino shooting, and not an ISIS-directed one, like the Bataclan theater attack in Paris.

Congressman Adam Schiff, a California Democrat, said in a press release that the attack appears to be an “ISIS-inspired act of terrorism.”

He said Mateen declared his allegiance to ISIS before the assault, according to local law enforcement. Schiff is the ranking member on the House Permanent Select Committee on Intelligence and said he received a preliminary briefing on the attack.

“This attack is so painfully reminiscent of the terrible attack at the Batlaclan Theatre in Paris, and other ISIS-inspired attacks in recent years,” Schiff said. “The fact that this shooting took place during Ramadan and that ISIS leadership in Raqqa has been urging attacks during this time, that the target was an LGBT night club during Pride … Whether this attack was also ISIS-directed, remains to be determined.”

The FBI has not confirmed Schiff’s statement.

Read more about Mateen at the link below:

Read more about Omar Mateen in Spanish at AhoraMismo.com: