Fifty people have been killed, including the assailant, and at least 53 injured in an attack inside a gay nightclub in the US state of Florida, authorities said, in the worst mass shooting in U.S. history.
Authorities identified the shooter on Sunday as Omar Mateen, a 29-year-old man born in New York with Afghan origins.
Mateen, who was armed with an assault-type rifle and a handgun, was killed in a shootout with at least 11 police officers inside the Pulse nightclub in Orlando.
Ron Hopper, special FBI agent in charge of the Orlando office, confirmed that Mateen was interviewed twice by the agency in 2013, after he made "inflammatory comments" to co-workers alleging possible "terrorist ties".
In 2014, authorities interrogated Mateen for possible ties to an American suicide bomber.
In both cases, the FBI closed the investigations as they turned out to be "inconclusive" at that time, Hopper said.
Hopper also confirmed media reports that Mateen made 911 calls to police early on Sunday, and referred to the Islamic State of Iraq and the Levant (ISIL also known as ISIS) group.
In a televised statement, President Barack Obama condemned the shooting as "an act of terror and an act of hate", calling the shooter "a person filled with hatred".
"As Americans, we are united in grief and outrage," he said, adding that the attack is "a further reminder of how easy it is for someone to get their hands on a weapon" and commit violence in the US.
The injured, many in critical condition, were transferred to nearby hospitals. Among those injured was one police officer, whose kevlar helmet was hit by a round from the suspect.
The suspect exchanged gunfire with a police officer working at the club, which had more than 300 people inside. The gunman then went back inside and took hostages, Mina said.
Around 5am, authorities sent in a SWAT team to rescue the hostages.
Christopher Hansen said he was in the VIP lounge of the club when he heard gunshots. He continued to hear shooting even after he emerged and police urged people to back away from the club. He saw the wounded being tended to across the street.
Florida Governor Rick Scott has declared a state of emergency in Orlando. Police said they carried out a "controlled explosion" at the club hours after the shooting broke out, while entering the nightclub.
This shooting is just another one of the many that has terrorized the U.S. and the world alike.
