Orlando mass shooter called 911 to ‘pledge his allegiance to IS’
* Islamic State militants claim responsibility for attack
* 'Police identify man as Omar Mateen (29)
* Deadliest mass shooting in U.S. history
* At least 53 wounded in rampage at "Pulse" club in Orlando
* Witnesses describe chaos
A gunman killed 50 people at a packed gay nightclub in Orlando, Florida on Sunday in the worst mass shooting in U.S. history which the US President described as an act of terrorism.
Police killed the shooter, who was identified as Omar S. Mateen, a Florida resident. However Mateen reportedly called emergency services and and swore allegiance to the leader of Islamic State shortly before the massacre.
Shortly before the attack, Mateen, who was born in New York to Afghan parents, called 911 and pledged allegiance to Abu Bakr al-Baghdadi, law enforcement officials told NBC News.
Islamic State's Amaq news agency said that the Islamist militant group was responsible for the shooting that killed at least 50 people in a massacre at a gay nightclub in Orlando, Florida.
"The armed attack that targeted a gay night club in the city of Orlando in the American state of Florida which left over 100 people dead or injured was carried out by an Islamic State fighter," Amaq said
Omar S. Mateen referenced the brothers who carried out the 2013 Boston Marathon bombing, a Massachusetts State Police spokesman said on Sunday.
"During a conference call with federal law enforcement officials a short time ago, Massachusetts State Police and other local law enforcement authorities learned that the Orlando nightclub gunman, during his rampage, pledged allegiance to ISIS and referenced the Tsarnaev brothers," state police spokesman David Procopio said in an e-mail.
The Tsarnaev brothers killed three people and injured more than 260 in the April 15, 2013, attack. Tamerlan Tsarnaev, 26, died four days later during a gunbattle with police while Dzhokhar Tsaranev, now 22, has been sentenced to death for his role in the attack
However, the killer's father insisted the shooting had nothing to do with religion. Instead, he said, Mateen was enraged after seeing two men kissing in downtown Miami months ago.
Pulse Shooting: The shooter inside the club is dead.— Orlando Police (@OrlandoPolice) June 12, 2016
Mateen "saw two men kissing each other in front of his wife and kid and he got very angry," Mir Seddique told NBC News.
They were kissing each other and touching each other and he said, 'Look at that. In front of my son they are doing that.' And then we were in the men's bathroom and men were kissing each other."
The father said the family is "in shock like the whole country."
Pulse nightclub shooting: Approximately 20 people dead inside the club.— Orlando Police (@OrlandoPolice) June 12, 2016
U.S. officials cautioned, however, that they had no immediate evidence of any direct connection with Islamic State or any other foreign extremist group.
US President Barack Obama called the Orlando mass shooting at a gay nightclub in which 50 people died, an "act of terror" and an "act of hate".
Pope Francis has expressed "horror and condemnation" over the "homicidal folly" of the Florida nightclub massacre.
Fifty-three people were wounded in the rampage, which Orlando Mayor Buddy Dyer said was the deadliest single U.S. shooting incident, eclipsing the 32 people killed in the 2007 massacre at Virginia Tech university.
"Today we're dealing with something that we never imagined and is unimaginable," Dyer said, more than doubling an earlier estimate that about 20 bodies had been found.
Pulse shooting: In hail of gunfire in which suspect was killed, OPD officer was hit. Kevlar helmet saved his life. pic.twitter.com/MAb0jGi7r4— Orlando Police (@OrlandoPolice) June 12, 2016
A police officer working as a security guard inside the Pulse nightclub, which has operated in downtown Orlando since 2004 and was hosting some 350 revelers, exchanged fire with the suspect at about 2 a.m. (0600 GMT), police officials said.
"Everyone get out of pulse and keep running," the club's management wrote on Facebook as the incident unfolded.
A hostage situation developed, and three hours later SWAT team officers used armored cars to storm the club before shooting dead the gunman. It was unclear when the victims were killed.
Dozens of terrified patrons, some of whom had been hiding in restrooms, were rescued. One officer was injured when he was hit in his helmet while exchanging fire with the gunman, police said.
Representative Adam Schiff, the top Democrat on a congressional intelligence committee, noted that the shooting took place during Ramadan, and that 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.
'DIFFERENT KIND OF CASE'
If confirmed as an act of terrorism, it would stand as the deadliest such attack on U.S. soil since Sept. 11, 2001, when al Qaeda-trained hijackers crashed jetliners into New York's World Trade Center, the Pentagon and a field in Pennsylvania, killing some 3,000 people.
A pair of ethnic Chechen brothers killed three people and injured more than 260 with a pair of homemade pressure-cooker bombs at the Boston Marathon in April 2013
Asked if the FBI suspected the gunman might have had inclinations toward militant Islam, including a possible sympathy for Islamic State, Ronald Hopper, an assistant FBI agent in charge, told reporters: "We do have suggestions that the individual may have leanings toward that particular ideology. But right now we can't say definitively."
U.S. Senator Marco Rubio of Florida, who sits on the Senate intelligence and foreign relations committees, told CNN he understood that the gunman had worked for a security company and so would have undergone some background checks.
"Over the next couple of days they're going to be looking to see where this individual was inspired to carry out this horrifying act of terrorism," Rubio said. "I think we're going to be talking about a very different kind of case here soon."
President Barack Obama ordered the federal government to provide any assistance needed to Florida police investigating the shooting, the White House said. He was due to speak later Sunday.
The attacker was carrying an assault rifle and a handgun, Orange County Sheriff Jerry Demings said. He was also carrying an unidentified "device", Orlando Police Chief John Mina said earlier.
Video footage showed police officers and civilians carrying some people away from the club and bending over others on the ground. Dozens of police cruisers, ambulances and other emergency vehicles could be seen in the area.
"It's definitely a tragedy not only for the city but for our entire nation," Mina told reporters. "We believe this is a tragedy that could happen anywhere in the United States of America, and what we need to do is continue to be vigilant."
Pulse, which was crowded for a Latin music night, describes itself on its website as more than "just another gay club." One of the founders and owners, Barbara Poma, opened it more than a decade ago in an effort to keep alive the spirit of her brother, who died after battling HIV.
It was the second deadly shooting at an Orlando night spot in as many nights. Late Friday, a man thought to be a deranged fan, fatally shot singer Christina Grimmie, a former contestant on "The Voice", as she was signing autographs after a concert.
The top Democrat on a congressional intelligence committee said local law enforcement believed the suspect in Sunday's deadly Orlando shooting had pledged allegiance to the Islamic State militant group.
"The fact that this shooting took place during Ramadan and that ISIS leadership in Raqqa has been urging attacks during this time, that the target was an LGBT night club during Pride, and - if accurate - that according to local law enforcement the shooter declared his allegiance to ISIS, indicates an ISIS-inspired act of terrorism," Representative Adam Schiff said in a statement.
Schiff is a member of the House Intelligence Committee
The choice of target was especially heart-wrenching for members of the U.S. lesbian, gay, bisexual and transgender community, LGBT advocacy group Equality Florida said in a statement.
"Gay clubs hold a significant place in LGBTQ history. They were often the only safe gathering place and this horrific act strikes directly at our sense of safety," the group said. "We will await the details in tears of sadness and anger."
Orlando has a population of 270,930 and is the home of the famed Disney World amusement park and many other tourist attractions that attracted 62 million visitors in 2014.
It was the second deadly shooting at an Orlando night spot in as many nights. Late Friday, a man thought to be a deranged fan fatally shot singer Christina Grimmie, a former contestant on "The Voice", as she was signing autographs after a concert.