Fifty people were killed and 53 injured at a gay nightclub in Orlando, Florida, in the worst mass shooting in US history. Authorities are investigating the massacre as a potential terrorist attack. 

Clubgoers fled the dance floor chaos in the early hours in a rush for safety, as a local police officer moonlighting as a security guard exchanged shots with the attacker, identified as Omar Mateen, a US citizen from Port St Lucie, Florida. Mateen, whose parents are from Afghanistan, was killed as police stormed the club. 

FBI special agent in charge Ron Hopper told reporters “we do have suggestions that [the] individual might have leanings toward” Islamist extremism. But the bureau has not yet classified the killings as either terrorism or an anti-gay hate crime, he added.