Orlando shooting: 50 killed in worst assault in US since 9/11; Obama calls it 'terror act', emergency declared

The overnight shooting at a gay nightclub that left 50 dead and 53 wounded is "clearly an act of terror," Florida Governor Rick Scott said Sunday.

Florida: In the worst mass shooting in US' history, at least 50 people were killed and 53 others injured when a "lone wolf" gunman opened fire early on Sunday in a gay nightclub in Orlando, Florida, where a state of emergency has been declared. 

US President Barack Obama was briefed on the mass shooting, which police described as an act of terrorism.

"Although it's still early in the investigation, we know enough to say that this was an act of terror and an act of hate," Obama said, later ordering flags at half-staff as an act of mourning.

Obama also expressed heartbreak over the "horrific massacre", branding it an act of terror and hate.

The US President, however, did not mention Islam or Islamic terrorism, as being blamed by some of his political opponents.

Hours after the untoward incident took place, while addressing a press conference, Florida Governor Rick Scott said, "The overnight shooting at a gay nightclub that left 50 dead and 53 wounded is "clearly an act of terror."

"For somebody to go in there and be an active shooter and take that number (of lives) ... is clearly an act of terror," the Republican said.

Florida Governor Rick Scott issues state of emergency in Orange Country, following deadly mass shooting. pic.twitter.com/6XaDucRdr0 — NBC Nightly News (@NBCNightlyNews) June 12, 2016

LIVE on #Periscope https://t.co/knyLCPgmVj — Orlando Police (@OrlandoPolice) June 12, 2016

Reacting over the incident, US Congressman Alan Grayson said it was "no coincidence" the attack happened in a gay club.

"Today we are dealing with something that we never imagined and is unimaginable," Mayor Dyer said, adding that there was "an enormous amount of havoc" and "blood everywhere".

"Because of the scale of the crime I've asked the [Florida] governor to declare a state of emergency," he said.

"We're also issuing a state of emergency for the city of Orlando so that we can bring additional resources to bear to deal with the aftermath."

Meanwhile, an outpouring of anger toward the lax US gun control policy was witnessed on social media after a the shooting spree took place here.

"When will the USA learn & introduce tighter gun control? How many more have to needlessly die?" A twitter user named Dave Nelson lashed out, Xinhua news agency reported.

The sentiment was shared by fellow twitter user Tevin Wooten, who asked on his account: "Does anyone want to admit to a gun violence problem now?"

According to local police, the shooter, identified as a 29-year-old US citizen of Afghan descent, had an assault-type weapon and a handgun as he stormed the gay club at around 2:00 am local time (0600 GMT).

Furious gun control supporters are questioning why laws are still permitting people with radical thinking or mental illness to acquire assault weapons.

Since the attack, social media have been buzzing with discussions on the massacre, with over 700,000 tweets using the hashtag of "Orlando."

Around 100 people were at the nightclub at the time of the shooting, and the shooter was killed by police in a shoot-out.

The shooter has been identified as Omar Mir Seddique Mateen​. 

Omar Mateen, who killed 50 in #Orlando #nightclub. Police: possible radical Islamic leanings. No claim yet pic.twitter.com/DjX5U3woUE — Rita Katz (@Rita_Katz) June 12, 2016

A top US congressman said Mateen may have pledged allegiance to the Islamic State militant group, as per Reuters.

US officials cautioned, however, that they had no immediate evidence of any direct connection with Islamic State or any other foreign extremist group.

Fifty-three people were wounded in the rampage, which Orlando Mayor said was the deadliest single US shooting incident, eclipsing the 32 people killed in the 2007 massacre at Virginia Tech university.

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, as per police.

"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 added.

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.

US Presidential candidates took to twitter to express their grief and support to the victims' families.

"Horrific incident in FL. Praying for all the victims & their families. When will this stop? When will we get tough, smart & vigilant?" wrote Republican presumptive nominee Donald J Trump.

Horrific incident in FL. Praying for all the victims & their families. When will this stop? When will we get tough, smart & vigilant? — Donald J. Trump (@realDonaldTrump) June 12, 2016

Democratic presumptive nominee Hillary Clinton signed her tweet with "-H" as an indication she wrote the tweet herself, instead of her campaign's social media staff. "Woke up to hear the devastating news from FL. As we wait for more information, my thoughts are with those affected by this horrific act. -H."

Woke up to hear the devastating news from FL. As we wait for more information, my thoughts are with those affected by this horrific act. -H — Hillary Clinton (@HillaryClinton) June 12, 2016

'Different kind of case'

If confirmed as an act of terrorism, it would stand as the deadliest such attack on US 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

As per the Reuters, 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."

. @FBI is the lead national agency on the #pulseshooting Main National Press Office # 202-324-3691 — Orlando Police (@OrlandoPolice) June 12, 2016

(With Agency inputs)