MIAMI (AFP, REUTERS) - A state of emergency has been declared in Florida after a gunman opened fire inside a crowded gay nightclub in Orlando early Sunday (June 12), killing 50 people and injuring 53 in the worst mass shooting in US history.
Police killed the shooter, who was identified as Omar Mateen, 29, a Florida resident and US citizen who was the son of immigrants from Afghanistan. According to a Saudi Interior Ministry Security Spokesman, Mateen has visited Saudi Arabia in 2011 and 2012.
Mateen called 911 on Sunday morning and made comments saying he supported the Islamic State of Iraq and Syria, officials said.
"It has been reported that Mateen made calls to 911 this morning in which he stated his allegiance to the leader of the Islamic State," said Ronald Hopper, the FBI's assistant special agent in charge on the case.
US officials cautioned, however, that they had no conclusive evidence of any direct connection with Islamic State or any other foreign extremist group.
"We know enough to say this was an act of terror, an act of hate," Obama said in a speech from the White House. "As Americans, we are united in grief, in outrage and in resolve to defend our people."
US officials have reached no definitive judgment on the killer's precise motives, Obama added.
"We must spare no effort to determine what, if any, inspiration or association this killer may have had with terrorist groups," he said.
Fifty-three people were wounded in the rampage. It was the deadliest single US mass shooting incident, eclipsing the 2007 massacre of 32 people at Virginia Tech university.
A handgun and assault rifle were found on the shooter after he died, said an Orange County sheriff. Florida Governor Rick Scott has declared a state of emergency.
US authorities are "confident" that there are no additional threats to the country.
"We feel confident there are no immediate threats to the area or the United States of America," said FBI special agent Ronald Hopper, at an Orlando, Florida press conference following the shooting.
Police have not identified a possible motive, but AFP, quoting a Federal Bureau of Investigation (FBI) official, said the bureau was investigating the shooting as an "act of terrorism".
"Any time we have potentially dozens of victims in our communities, that I think we can qualify that as a terrorist activity. Whether that's a domestic terrorist or international one is something we'll get to the bottom of," said Danny Banks, of the Florida Department of Law Enforcement Office.
Asked whether there was any reason to believe there was a connection to Islamic terrorism, FBI special agent Ron Harper said investigators would be looking into "all angles".
"We do have suggestions that that individual may have leanings towards that particular ideology but we can't say definitively," he said.
Reuters reported that FBI was still determining if it was a hate crime, a terrorist act or a violent crime.
The father of the suspected gunman said on Sunday he believed his son was motivated by hatred of gays - not by his Muslim religion.
"This had nothing to do with religion," Mir Seddique told NBC News. He said his son, Omar Mateen, recently lashed out in his presence after witnessing a gay couple embracing in downtown Miami, and suggested the incident may have triggered the atrocity.
"He saw two men kissing each other in front of his wife and kid and he got very angry," Seddique told the network.
Representative Adam Schiff, the top Democrat on a congressional intelligence committee, noted that the shooting took place during Ramadan, and that the Islamic State of Iraq and Syria (ISIS) leaders in Syria have urged attacks during this time.
"The target was an LGBT nightclub during Pride, and - if accurate - that according to local law enforcement the shooter declared his allegiance to ISIS, (that) indicates an ISIS-inspired act of terrorism," Schiff said in a statement.
US President Barack Obama on Sunday ordered the federal government to provide any assistance necessary to local law enforcement officials investigating the shooting.
Obama was briefed on the shooting by Lisa Monaco, Assistant to the President for Homeland Security and Counterterrorism, the White House said in a statement.
Police said the shooter was dead, four hours after the incident began with a volley of gunfire in the Pulse nightclub in downtown Orlando, triggering a massive deployment of police and emergency vehicles.
"We can confirm this is a mass casualty situation," the Orlando police said on their Twitter account.
"The shooter inside the club is dead," they said in a separate tweet. Another tweet delivered after a briefing by the FBI the grim news that about 20 people had been killed inside the club.
It was the second shooting incident in the city in just over 24 hours, coming shortly after singer Christina Grimmie was shot dead late Friday (June 10) by a gunman who stormed a theater where she had just finished a gig.
Witnesses said the shooting erupted at around 2am local time (2pm Singapore time) amid throbbing music as the crowded club was nearing closing time.
Speaking to Sky News, clubber Ricardo Negron, who was inside when the shooting began, described how the gunman raked the club with bullets.
"People just dropped on the floor. I guess the shooter was shooting at the ceiling because you could see all the glass from the lamps falling," he told the network.
He described hearing "non-stop firing" which probably lasted less than a minute but felt like a lot longer.
"There was a brief pause in the shooting and some of us just got up and ran out the back. People have definitely been injured - or worse."
Emergency vehicles swarmed the area, with at least one crisis command vehicle at the scene.
"Shooting at Pulse Nightclub on S Orange. Multiple injuries. Stay away from area," Orlando police wrote on Twitter.
"There are injuries. I am not sure if there are any deceased at this time," a police dispatcher told AFP. "Officers are going in to search the building and to get people out."
The club advertises itself online as "Orlando's hottest gay bar." On its Facebook page, the club warned patrons: "Everyone get out Pulse and keep running."
Witness Christopher Hanson said he heard "loud banging noises, like gunshots going off." "I didn't see any of the actual shooters. I just saw bodies going down and I was ordering a drink at the bar.
"I fell down. I crawled out. People were trying to escape out the back. I just know that when I hit the ground, I was crawling and I hit my elbows and my knees," he told CNN.
He said there was "blood everywhere."
Rosie Feba was at the club with a friend when the shooting broke out.
"She told me someone was shooting. Everyone was getting on the floor," Feba told the Orlando Sentinel. "I told her I didn't think it was real, I thought it was just part of the music, until I saw fire coming out of his gun."
The incident came on the heels of a deadly shooting at the nearby Plaza Live Theater in which a heavily armed gunman shot and critically wounded singer Grimmie, a former contestant on the popular TV talent show The Voice.
She was rushed to hospital but died of her wounds. The theater is located less than four miles (6.4km) from Pulse nightclub.
The Plaza gunman, 27-year-old Kevin James Loibl, then killed himself.
He was found to be armed with two handguns, ammunition and a hunting knife, police said. His motive remains unknown.