Pulse attack gunman 'had strong indications of radicalisation'
A gunman who pledged his allegiance to Islamic State before he massacred 49 people at a US nightclub had "strong indications of radicalisation", the FBI said.
Officers blasted a hole in the wall of the Pulse club in Orlando, Florida, in a desperate effort to save revellers as Omar Mateen held hostages in a toilet at the gay nightclub.
FBI director James Comey said Mateen had come to its attention twice before the shooting and had been investigated for 10 months from May 2013 because he had made "inflammatory and contradictory" statements about ties to terrorist groups.
Mr Comey said that at the time the gunman claimed family connections to al Qaida and said he was a member of Hezbollah, which "is a Shia terrorist organization that is a bitter enemy of the so-called Islamic State."
Mateen admitted making the statements reported by his colleagues, but said he did it in anger because he thought they were discriminating against him and teasing him because he was Muslim
Agents closed the first investigation in early 2014, but Mateen's name came up in a separate FBI investigation in July that year, after he was linked to a Syria suicide bomber.
John Mina, chief of police at the City of Orlando Police Department, said Mateen barricaded himself in a toilet with around four or five hostages after shooting some of his initial victims and called the police, speaking in a "cool and calm" voice with crisis negotiators.
He also confirmed that when Mateen was on the phone to officers "there was allegiance to the Islamic State".
Authorities in Orlando confirmed 49 people were killed in the shooting in the early hours of Sunday, with 53 others injured. Mateen, was the 50th person to die.
He was killed by Swat officers when he opened fire at police after himself crawling out of the hole made to rescue the nightclubbers.
President Barack Obama called the massacre - the worst mass shooting in recent US history - an "act of terror", while Orlando mayor Buddy Dyer said: "We will not be defined by the act of a cowardly hater."
More than 300 people were inside the nightclub when the sound of gunfire was first heard just after 2am local time (7am British time).
The killer fired repeatedly before taking dozens of revellers hostage, leading to a stand-off lasting around three hours.
As Mateen, a 29-year-old bodybuilder of Afghan origin, held a small group in one toilet, around 15 to 20 people took cover in a second toilet opposite.
Speaking to reporters in Orlando, Mr Mina said: "Based on information made by the suspect and from the hostages and people inside, we believed further loss of life was imminent. I made the decision to commence the rescue operation and do the explosive breach."
Mateen fired on officers with a handgun and a "long gun", thought to be an AR-15 rifle, after he emerged from the club, before being killed.
A third weapon was also found in his vehicle, authorities said.
All the victims' bodies have now been removed from the club and FBI investigators are painstakingly working at the scene to reconstruct the night's events.
An ex-wife described Mateen, reportedly a regular at an Islamic centre in Orlando, as a violent bodybuilder who had a history of abusing steroids and was bipolar.
His father Seddique Mir Mateen told NBC news his son had recently been angered after seeing two men kissing while out with his young son, and he denied the killings had a religious motive.
In defiance of the attack, residents in Orlando queued in their hundreds to donate blood to help those in hospital being treated for their injuries.
Members of the LGBT (lesbian, gay, bisexual, transgender) community also held vigils in the state, scenes of solidarity which have been mirrored across the world.
Prime Minister David Cameron said he was "horrified" by the shootings, while Buckingham Palace said a personal message had been sent to Mr Obama saying the Queen and Duke of Edinburgh were "shocked" by the events in Orlando.