US authorities are investigating whether a gunman who killed 49 people at a gay nightclub in Orlando and declared his allegiance to so-called Islamic State militants had received any help in carrying out the massacre.
The FBI and other agencies were looking at evidence inside and on the closed-off streets around the Pulse nightclub, where New York-born Omar Mateen carried out the worst mass murder in US history, and the deadliest attack on US soil since the 11 September 2001 attacks.
Mateen, 29, the son of Afghan immigrants, was shot and killed by police who stormed the club with armored cars early on Sunday morning after a three-hour siege.
FBI Director James Comey said authorities were trying to determine Mateen's motives and there was no indication he was part of an organised terror network, although he may have been inspired by them.
"There are strong indications of radicalisation by this killer and of potential inspiration by foreign terrorist organisations," Mr Comey told reporters in Washington. "We're highly confident this killer was radicalised at least in some part through the internet."
Law enforcement officials searched for clues as to whether anyone had worked with Mateen on the attack, said Lee Bentley, the US attorney for the middle district of Florida.
"There is an investigation of other persons. We are working as diligently as we can on that," Bentley said at a news conference. "If anyone else was involved in this crime, they will be prosecuted."
Officials stressed they believed there had been no other attackers and had no evidence of a threat to the public.
Mateen's shooting spree began about 2am local time on Sunday (7am Irish time) when the club was packed with some 350 revelers.
Many fled as the gunman raked the crowd with bullets from an AR-15-style semi-automatic rifle and a pistol.
An initial wave of officers charged into the club and trapped Mateen in a bathroom, Orlando Police Chief John Mina told reporters. That allowed many patrons to flee, although others were trapped in the restroom with Mateen, leading to the standoff.
US President Barack Obama has said that the shootings at a Florida nightclub in which 49 people were killed is being treated as a terrorists investigation.
Doctors fear the death toll from the deadliest mass shooting in US history will rise, as the identities of the 49 people who were murdered began to emerge.
Mr Obama said there was no clear evidence that the shooter, Omar Mateen, had been directed by a larger terrorist network.
Speaking in the White House, he said that Mateen had been "inspired by various extremist information that was disseminated over the internet".
36 of the 49 victims of the attack by 29-year-old security guard Mateen, who massacred revellers and at least one employee at a gay nightclub in Orlando, have been named.
According to reports the bodybuilder telephoned police and pledged allegiance to the so-called Islamic State before he opened fire on the crowds with an assault rifle and handgun.
The militant group has since claimed responsibility for the attacks described by Mr Obama as an "act of hate".
Meanwhile it has emerged that the New York-born killer, who worked for security giant G4S, had been examined by counter-terror investigators several times in recent years.
More than 300 people were inside the Pulse nightclub at the time of the attack in the early hours of yesterday morning.
The killer, who also held hostages in a three-hour stand-off, died in a gunfight with Swat officers after they stormed the building.
He had fatally wounded at least 49 victims and injured dozens more.
Officials said 39 people died in the venue. 53 people, most in a critical condition, remain in hospital.
The majority of the patients were taken to the Orlando Regional Medical Centre. Trauma surgeon Dr Mike Cheatham warned: "I think we will see the death toll rise."
UPDATE: More names of those who lost their lives in #PulseShooting https://t.co/a0wekaZPtG
— Orlando Police (@OrlandoPolice) June 13, 2016
Memorials held globally for Orlando victims
Mateen was 'very short-tempered' - ex-wife
Mateen's ex-wife, Sitora Yusuify has said that he was emotionally disturbed with a violent temper.
Speaking to media in Colorado, Sitora Yusufiy said that she had been beaten and otherwise physically abused by Mateen during outbursts in which he would "express hated towards everything."
She said that she was "rescued" by family members just four months into their marriage that began in 2009 and ended in divorce.
Ms Yusuify said: "He would often get into fights with his parents, but as I was the only one in his life most of the violence was directed towards me.
She said Mateen aspired to be a police officer and had worked as a correctional officer at a detention centre for juvenile delinquents in Fort Pierce, Florida, and had once sought admission to a police academy.
Sitora Yusufiy, ex-wife of man who killed 50 people in Florida nightclub, said he was 'very short-tempered'https://t.co/diNA441Tq3
— RTÉ News (@rtenews) June 13, 2016
Mateen was known to the FBI after making inflammatory comments to co-workers about extremism in 2013.
He was questioned twice and investigated again in 2014 over potential links to an American suicide bomber, but the probe was dropped after he was deemed to be low-risk.
However he was not under surveillance and the FBI said he had legally purchased two firearms within the past week.
The 911 calls involving the shooter from Port St Lucie, Florida that featured conversations about IS before the massacre have been handed to investigators.
IS's Amaq news agency is understood to have issued a statement saying the massacre was "carried out by an IS fighter".
However US officials said it was possible that he was self-radicalised but not "under the command and control of ISIS".
Meanwhile his father, Seddique Mir Mateen, told NBC news that his son had recently been angered after seeing two men kissing while out with his young son and denied the killings had a religious motive.
This evening hundreds of people took part in a vigil in Dublin to remember those who died in the attack in Orlando.
It was organised by LGBT organisations GLEN, BeLonG To and TENI.
The names of those known to have died in the attacks were read out at the vigil and a moment's silence was also held for the victims.
The choir, Gloria, sang Somewhere Over the Rainbow.
Sillent vigil in Dublin for #Orlando pic.twitter.com/UePffm0Znr
— Helen Donohue (@Donohuereports) June 13, 2016
Candidates debate response
The attack reignited the debate over how best to confront violent Islamist militancy and immediately became a sharp point of disagreement in the campaign for the 8 November presidential election.
Wealthy businessman and presumptive Republican nominee Donald Trump lashed out at Mr Obama over the shooting massacre, saying it is possible the president "doesn't want to see what's happening."
In a series of television interviews, he questioned his motivation and said Mr Obama would never solve the national security problem. In a speech in New Hampshire, Mr Trump reiterated his call for a temporary ban on Muslims entering the country but said it could be lifted once they were properly screened. "We must find out what is going on," Mr Trump said. "We need to tell the truth about how radical Islam is coming to our shores."
Presumptive Democratic nominee Hillary Clinton, in her first campaign stop since the shootings, said in Cleveland the US should walk a fine line in bolstering security without demonising Muslims.
She also called for tougher gun safety measures and increased efforts to remove Islamic State messages from the internet.
The attack early on Sunday occurred in the heart of Orlando, about 25km northeast of the Walt Disney World Resort. The city is one of the most popular tourist destinations in the US, drawing some 62 million visitors a year.
Moore points to culture of fear and ignorance
Film-maker, Michael Moore, who won an Oscar for Bowling for Columbine, his 2002 documentary examining America's gun culture, has said that it needs to be stated that the gunman responsible for the Florida killings was a New Yorker; an American, who committed mass murder.
Mr Moore, who is in Ireland this evening, told RTÉ's Six One that there is a culture of fear and ignorance in the US which has made it intractable to tighten up gun laws.
He said the US is a perpetrator of violence around the world, adding that America has both state sponsored violence and personal violence, where people reach for a gun.
He said that Mr Trump's success is due to a manipulation of a Republican dumbed-down population, who own guns.
He said that Mr Trump should be taken very seriously for November.
