The shooter was identified as Omar Mateen, who called 911 on Sunday morning (local time) and made comments saying he supported the Islamic State (IS) militant group, officials said.
But US officials cautioned they had no conclusive evidence of any direct connection with IS or any other foreign extremist group.
Mateen was born to Afghan parents in 1986 and lived in Port St Lucie, Florida, about two hours’ drive from Orlando.
The suspect’s father told NBC news his son may have been motivated by homophobia and not by his Muslim faith.
“This had nothing to do with religion,” Mir Seddique told the network, recalling a recent incident in downtown Miami.
“He saw two men kissing each other in front of his wife and kid and he got very angry,” the father said, apologising to the victims.
US President Barack Obama expressed heartbreak at the “horrific massacre”, branding it an act of terror and hate.
“Although it’s still early in the investigation, we know enough to say that this was an act of terror and an act of hate,” Mr Obama said, later ordering flags at half-staff as an act of mourning.
On gun violence Mr Obama said: “To actively do nothing is a decision as well.”
FBI official Ronald Hopper told reporters officials were “confident” there was no immediate further threat to the area, or to the United States.
Because of the scale of the crime, however, Orlando’s Mayor declared a city-wide state of emergency and has asked the Florida Governor to take the same measure state-wide.
“More likely than not it was an ideologically motivated attack,” Florida Congressman Alan Grayson said.
“It might be that we’ve seen the commission of an awful hate crime.”
Florida officials invited a local Islamic leader to address the media in a bid to pre-empt a possible backlash against the Muslim community.
dad had a good story to be quoted within 12 hours..good memory dad..
“He saw two men kissing each other in front of his wife and kid and he got very angry,” the father said, apologising to the victims.”
so he went and killed 50 people?
known to the fbi and multiple shooters mentioned again..thats a lot of dead people from one person..but i guess its possible..
thoughts are with the victims..such carnage..