The gunman who killed 50 people at a gay nightclub in Orlando has been identified

The gunman who killed 50 people at a gay nightclub in Orlando and wounded dozens more has been identified by relatives and law-enforcement officials as 29-year-old Omar Saddiqui Mateen from Fort Pierce, Florida, according to multiple reports.

Mateen entered the nightclub armed with an AR-15 assault rifle and a handgun just before 2 a.m. Sunday morning and opened fire, according to law-enforcement officials' description of the incident.

He then barricaded himself inside the nightclub and took hostages, and was negotiating with police when he gave them his name, according to CNN.

A SWAT team entered the club about three hours later, after ensuring Mateen did not have a bomb, and shot the suspect.

At least 42 people have been transported to local hospitals, and Orlando police have declared a state of emergency. It is the deadliest shooting in US history.

Law enforcement confirmed that the incident is being treated as an act of terrorism. Both domestic and international terrorism are being investigated. The FBI special agent in charge said there were indications the Mateen subscribed to a radical Islamic ideology.

Mateen, a US citizen, was born in 1986 to parents from Afghanistan, multiple media outlets have reported. An FBI representative said he "was organized and well-prepared," and not from the area.

"I call on my fellow faith leaders...please pray for the victims and their families at this hour," the leader of Orlando's Islamic community,Muhammad Musri, said during a press conference.

"I want to caution anyone from rushing to judgment or sensationalizing the story, because we do not want the focus of the story to shift from what it is: a horrible tragedy. We are mourning, we are heartbroken," he said.

About 320 people were inside the nightclub at the time of the shooting, according to Orlando police.

"Everyone get out of pulse and keep running," the nightclub said on its Facebook page at 2:09 a.m.

Pulse markets itself as "Orlando's premier gay nightclub." It was Latin night at the club, according to its Facebook page.