A gunman opened fire inside a gay nightclub in Orlando, Florida, early Sunday morning, killing at least 50 people and injuring dozens more in what authorities classified as a terror incident.

The gunman was killed by police following the attack, which occurred at about 2 a.m. inside the Pulse Nightclub.

Orlando Mayor Buddy Dyer said at a news conference Sunday morning that at least 50 were killed in the attack and 53 others wounded. Officials said earlier Sunday that the gunmen killed approximately 20 people and wounded 42 inside the club.

During remarks from the White House Sunday afternoon, President Obama called the attack an "act of terror."

"We know enough to say this was an act of terror and an act of hate," Obama said. "The FBI is appropriately investigating this as an act of terrorism. … What is clear is he was a person filled with hatred."

Multiple outlets have identified the gunman as Omar Mateen, citing law enforcement officials. CBS News reported that Mateen is a U.S. citizen from Port St. Lucie, Florida, born to Afghan parents in 1986. Reports have indicated that the suspect pledged allegiance to ISIS, the terror group that claimed responsibility for devastating attacks in Paris and Brussels.

Authorities classified the shooting as a "domestic terror incident." Ron Hopper, an FBI agent in charge of the investigation, indicated Sunday morning that the gunman may have had connections to jihadist terror groups.

"At this time we’re looking at all angles right now," Hopper stated at a news conference, according to ABC News. "We do have suggestions that that individual may have leanings towards that, that particular ideology. But right now we can’t say definitively, so we’re still running everything around."

Shooting at Pulse Nightclub on S Orange. Multiple injuries. Stay away from area. pic.twitter.com/5Di2mc6XUY — Orlando Police (@OrlandoPolice) June 12, 2016

FBI officials noted that the gunman was "organized and well-prepared." He was not from the area, officials said.

A police officer who was working as a security guard at the club exchanged fire with the shooter at about 2 A.M., after which the suspect began taking hostages inside of the club. The gunman was armed with an assault rifle, a handgun, and what officials described as "some kind of device." A SWAT team entered the club to rescue the hostages at about 5 A.M., officials said, and the gunmen was killed in a fire fight with the officers.

There were more than 300 people inside the club at the time of the attack.

Rep. Adam Schiff (D., Calif.), the ranking member of the House Intelligence Committee, said on CNN that he had been informed the suspect pledged allegiance to ISIS.

"What I’ve heard from the Department of Homeland Security this morning is that, according to local police, he made a pledge of allegiance to ISIL," Schiff said, using another name for the terror group.

"[He] was heard praying in a foreign language, and I don’t know if this was at some point during the course of the shooting, but that's what I'm hearing, obviously second-hand, coming ultimately from local police," he said.

Schiff said that the circumstances of the attack were "highly indicative" of an attack inspired by ISIS, though he added that it is unclear whether the attack was directed by the group.

NBC News later reported that Mateen phoned 911 moments before Sunday morning’s attack to pledge allegiance to ISIS.

The Florida Department of Law Enforcement is currently investigating the attack as an act of terrorism and looking to determine whether it is "domestic or international" terrorism.

The governor of Florida declared a state of emergency following the attack.

Florida Gov has declared a state of emergency. City of Orlando also declared state of emergency. — Orlando Police (@OrlandoPolice) June 12, 2016

The White House said in a statement around 9 a.m. that President Obama had been briefed on the shooting by Lisa Monaco, his adviser on homeland security and counterterrorism.

"Our thoughts and prayers are with the families and loved ones of the victims. The President asked to receive regular updates as the FBI, and other federal officials, work with the Orlando Police to gather more information, and directed that the federal government provide any assistance necessary to pursue the investigation and support the community," the White House said.

This post will be updated as further information becomes available.