ORLANDO: Police revealed new details on the agonizing three-hour stand-off and brutal end to the Orlando gay club massacre on Monday as America grappled with the implications of the worst terror attack on its soil since 9/11.
The Islamic State group claimed slain shooter Omar Mateen was acting as "one of the soldiers of the caliphate in America" when he attacked the Pulse club in the central Florida city, a siege that ended when police stormed the venue.
But investigators are probing whether he was a jihadist on a mission or a vicious "lone wolf" inspired by the group's propaganda to carry out what President Barack Obama dubbed "an act of terror and an act of hate."
Forty-nine people were killed and 53 others wounded in the attack, which was also the deadliest mass shooting in US history.
The slaughter triggered worldwide shock and outrage, but has also raised questions about US counter-terror strategy and gun laws. The suspect was allowed to legally buy a rifle and handgun despite raising red flags.
Mateen, a 29-year-old American of Afghan descent, called police in the midst of his rampage to pledge allegiance to the Islamic State group, and the FBI admitted it had previously investigated him but cleared him of extremist ties.
According to CNN, citing an unnamed US official, the New York-born security guard made a religious pilgrimage to Saudi Arabia and visited the United Arab Emirates in 2011 and 2012.
But no evidence has yet emerged linking him to a foreign extremist group before the attacks, and relatives and acquaintances painted a picture of a violent and unstable young man who had beat his ex-wife and expressed homophobic views.
The relatives of the dead and wounded -- clubgoers celebrating at one of Orlando's most prominent gay venues at the start of Gay Pride month -- were informed early Monday that police had identified 48 of the 49 victims.
Another 53 were wounded, but city mayor Buddy Dyer said many more were saved by police action, including when they crashed an armored car through a wall to allow patrons to escape as the gunman barricaded himself in a bathroom with hostages.
"We will not be defined by the act of a cowardly hater. We will be defined by how we respond, how we treat each other," Dyer declared, before police recounted how a gunbattle at the entrance to the club became a bloody hostage drama.
As the club was closing at around 2:00 am, Mateen began a gun battle with an off-duty officer working at the club. More officers responded to the scene, and the gunman fell back to the bathroom, where he apparently seized hostages.
"At that time, we were able to save dozens and dozens of people," Orlando police chief John Mina told reporters.
Witness Janiel Gonzalez described scenes of mayhem as the gunman sprayed revelers with bullets.
"It was like complete chaos," witness Janiel Gonzalez told AFP. "It was like a scene out of a movie. People were screaming 'Help me, help me, I'm trapped!'"
Mina said he later made the difficult decision to burst into the club after Mateen made comments about "bomb vests , about explosives."
"We believed that further loss of life was imminent," Mina told reporters at a morning press conference.
"We knew that was the right thing to do and believe we prevented a future loss of life and saved many, many lives."
Police used explosives and a BearCat armored car to punch a hole in the wall of the club. Dozens more survivors surged out of the breach, but Mateen opened fire and was cut down by police.
Officials in Orlando, a resort city famous worldwide as the home of Walt Disney World and other amusement parks, were stunned by the tragedy but vowed that the community would pull together.
"This is not a war zone that we are living in. This is a civilized society and we had to deal with something unthinkable," Orange County Sheriff Jerry Demings said.
The attacks triggered solidarity vigils by gay and lesbian groups -- and their supporters -- across the country and abroad. More than 100,000 marched in Los Angeles at an already planned Pride parade.
In New York, the Tony Awards for musical theater went ahead as planned but were dedicated to the victims of the massacre.
The Empire State building went dark, while the spire of One World Trade Center was lit in the rainbow colors of the gay pride flag.
But no mood of national outrage could survive long in the crucible of America's 2016 presidential race, and presumptive Republican presidential nominee Donald Trump seized upon it to launch an attack on Obama and his Democratic rival Hillary Clinton.
"I think you're going to see tremendous pressure now on these weak politicians that don't know what they're doing, like our president," Trump said in an interview with Fox News.
"The man has no clue. He doesn't know what he's doing and Hillary Clinton is going to be worse than him," he declared, arguing that Obama had failed to confront the threat of "radical Islam" because of "political correctness."
Trump accuses Obama of seeking to bring hundreds of thousands of Syrian migrants to the United States. In reality, the White House's goal this year is to offer sanctuary to only 10,000 of the most vulnerable war refugees.
Clinton pushed back against the charge that she is unwilling to identify Islamist extremism as a threat, telling MSNBC: "We have to defeat radical jihadist terrorism or radical Islamism, whatever you call it. It's the same.
"But we cannot demonize, demagogue and declare war on an entire religion... it plays into the hands of ISIS and other jihadist terrorists. And so that's why I have been focused on how we tackle this issue of self-radicalization."