Deadliest mass shooting in US history: 49 dead, 53 injured in Orlando gay club massacre

Forty-nine people have been killed and 53 injured in the Orlando night club shooting, the city mayor said during a press briefing. The shooting is the deadliest in recent US history.

The Orlando attack was “the most deadly shooting in American history,” US President Barack Obama said.

“We’ve reached no definitive judgment on the precise motivation of the killer,” Obama told reporters at the White House around 2:00pm Eastern time. “What is clear is that he was a person filled with hatred.”

READ MORE: Orlando bloodbath: Multiple deaths after shooting rampage at gay nightclub

“Attacks on any American, regardless of race, ethnicity, religion or sexual orientation, are an attack on all of us,” the president said.

“Will not change who we are,” Obama said. “We will not give into fear or turn against each other. Instead, we’ll stand united as Americans.”

The process of removing the victims from the club continues, according to the Orange county sheriff. Some victims of the shooting are undergoing surgery with a number of them in critical condition, hospital officials told journalists during the briefing, Reuters reports.

Initially police announced that 50 people had been killed, apparently mistakenly counting Mateen as a victim.

"Today we're dealing with something that we never imagined and is unimaginable," Dyer said. "It is with great sadness I share that we not have 20 but 50 casualties (dead), in addition to the shooter. There are another 53 ...hospitalized."

With 49 people dead, the Orlando shooting has become the deadliest massacre in US history, eclipsing the 2007 massacre at Virginia Tech University, which left 32 dead.

Both the Florida governor and the city of Orlando has declared a state of emergency following the deadly shooting.

READ MORE: Orlando nightclub shooter ID'd as US citizen Omar Mateen from Florida - report 

The suspect behind the shooting has been identified as 29-year-old US citizen Omar Mateen, US media reported. The CBS network added that the FBI is currently checking whether he was linked to extremists.

The shooter was of Afghan descent and had weapons training, Peter King, US congressman and chairman of the House subcommittee on counterterrorism and intelligence, told US media.

A police officer, who worked in the club as a security guard, was injured in the incident as he exchanged fire with the shooter at 02:00 local time (06:00 GMT), Reuters reports, citing police sources.

The attacker took hostages in the club, but three hours after the attack started a SWAT squad stormed the building and shot the gunman dead. It remains unclear when the attacker shot his victims. The shooter was carrying an assault rifle and a handgun, according to Orange County Sheriff Jerry Demings.

The gunman was also carrying an unidentified “device,” Orlando Police Chief John Mina said.

Obama thanked the police and first responders for quick and courageous action that saved lives, and said that the full resources of the federal government would be made available for the investigation.

The FBI is still trying to establish whether the massacre was a hate crime or a terrorist act.