NEW YORK (AA) – At least 53 people are dead and 50 injured following what many are calling the worst mass shooting in U.S. history, Orlando, Florida, officials confirmed Sunday.

The shooter has been identified by Congressman Alan Grayson as Omar Mateen, a U.S. citizen in his late 20s residing in Port St. Lucie, Florida. His parents are of Afghan origin.

Mateen was a ‘known quantity’ to federal law enforcement before he killed 53 people in the worst mass shooting in U.S. history.

Omar Mateen of Port Saint Lucie, Florida, came to the attention of federal authorities twice prior to being identified as the gunman in the Orlando nightclub mass shooting, a senior law enforcement source told The Daily Beast.

The senior law enforcement source reports that Mateen became a person of interest in 2013 and again in 2014. The Federal Bureau of Investigation at one point opened an investigation into Mateen but subsequently closed the case when it produced nothing that appeared to warrant further investigation.

“He’s a known quantity,” the source said. “He’s been on the radar before.”

Mateen was a U.S. citizen; his parents are from Afghanistan, CBS News reports.

Father Mir Mateen told NBC News that the sight of two men kissing angered his son.

“We are saying we are apologizing for the whole incident,” the father added. “We weren’t aware of any action he is taking. We are in shock like the whole country.”

The attack, he said, “has nothing to do with religion.”

An FBI agent told reporters the suspect has not been positively identified by his next of kin, while adding there were no other threats being investigated.

A state of emergency has been declared in the state of Florida, Mayor Buddy Dyer told media.

This is “a tragedy of unimagined proportions”, he told local WESH 2 television, adding, “We are a strong, resilient community. We are going to support those families” who are mourning loved ones killed in the shooting.

Grayson said the attack was “ideologically motivated,” confirming earlier police reports that Mateen had “radical Islamic leanings.” An FBI official said the nationality of family members was “indicative” of Islamic extremism involved in the incident.

The attack at a gay nightclub may have been an “awful hate crime” against the LGBT community, according to the congressman.

A hospital official at the briefing said “many” of the injured were in critical condition.

Anxiety and desperation were reported at hospitals in the area as families arrived to find information about their loved ones. Local TV stations are making appeals for blood donations.

WESH 2 footage taken near a location where donations are accepted showed hundreds of citizens turning up to donate blood, forming a long line that circled the building.

Muhammad Nusri, a senior imam with the Islamic Society of Central Florida, said he was “heartbroken” and stood in solidarity with city officials “in this hour of horror was brought upon our city”.

Nusri said the perpetrator was “not known to be connected with any network” and urged the media to exercise “caution from rushing to judgment and sensationalizing the story.”

The attack at Pulse Club took place at around 2 a.m. (0600GMT), Orlando police chief John Mina said.

Mina said the police decided to “rescue hostages that were in there” at 5 a.m. (0900GMT), suggesting Mateen had free reign inside the club for nearly three hours.

Nine officers entered the club and engaged the attacker, who carried an AR-15 type assault rifle, a handgun, and a “suspicious device” police officers have yet to identify but have cleared from the area.

The shooter was killed and one officer was injured in the shootout, during which 30 people were rescued.
WESH 2 reported that officers used a distraction explosion as a police vehicle drove through the club’s wall to engage the shooter.

Another device, potentially an explosive, was found in the shooter’s van, police said.

Orlando Police Department later tweeted a picture of the Kevlar helmet the injured officer was wearing, with a visible bullet hole right in front.

The White House issued a statement said President Barack Obama was receiving regular updates about the situation. “Our thoughts and prayers are with the families and loved ones of the victims,” it said.

Democratic presidential candidate Hillary Clinton tweeted briefly about the shooting. “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,” she said.

Republican candidate Donald Trump also weighed in on the social media platform. “Really bad shooting in Orlando. Police investigating possible terrorism. Many people dead and wounded.”

Mayor Dyer said the club has been cleared and there was no continued threat to the community, while confirming as many as 300 people were inside at the time of the attack.

The shooting was first reported online at 2.09 a.m. by the club on their Facebook page: “everyone get out of pulse and keep running”.

Three hours later, Orlando police, on its official Twitter account, described it as a “mass casualty situation”.

A video captured outside the club and shared online carried the sounds of more than a dozen shots fired in rapid succession.

Dyer described the incident as a “horrific crime” that will have a “lasting effect” on the local community, while an Orange County sheriff said the shooting was treated as a “domestic terror incident”.

Pulse calls itself “more than just another nightclub” aimed at raising awareness about the LGBT community.

The area around the shooting remains under police lockdown as a large-scale investigation continues.
Author Canberk Yüksel

[Map of Central Florida. By Info Eagle/Creative Commons]