Shooting rampage at Florida nightclub

A gunman killed 49 people and injured 53 others in a crowded gay nightclub in Florida early on Sunday, June 12 before police shot him dead in what U.S. authorities described as a “terrorism incident.”

A police officer working as a security guard inside the Pulse club exchanged fire with the suspect at about 2 a.m., police officials said.

A hostage situation quickly developed, and three hours later a squad of officers entered the club and shot dead the gunman. It was unclear when the gunman shot the victims.

President Barack Obama described the worst mass shooting in U.S. history as “an act of terror” and “an act of hate,” saying the massacre of 49 people at a packed gay nightclub in Orlando, Florida was an attack on all Americans. (AP/Reuters)

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Shooting rampage at Florida nightclub

Orlando Police officers direct family members away from a fatal shooting at Pulse Orlando nightclub in Orlando, Fla., Sunday, June 12, 2016. (AP Photo/Phelan M. Ebenhack)

Shooting rampage at Florida nightclub

Jermaine Towns, left, and Brandon Shuford wait down the street from a multiple shooting at a nightclub in Orlando, Fla., Sunday, June 12, 2016. Towns said his brother was in the club at the time. A gunman opened fire at a nightclub in central Florida, and multiple people have been wounded, police said Sunday. (AP Photo/Phelan M. Ebenhack)

Shooting rampage at Florida nightclub

A handout photograph made available by Univision Florida Central showing a view of the general scene following a shooting at Pulse Nightclub in Orlando, June 12, 2016. (EPA/UNIVISION FLORIDA CENTRAL)

Shooting rampage at Florida nightclub

Police cars and fire trucks are seen outside the Pulse night club where police said a suspected gunman left multiple people dead and injured in Orlando, Florida, June 12, 2016. (Orlando Police Department/Handout via REUTERS)

Shooting rampage at Florida nightclub

An injured man is escorted out of the Pulse nightclub after a shooting rampage, Sunday morning June 12, 2016, in Orlando, Fla. (AP Photo/Steven Fernandez)

Shooting rampage at Florida nightclub

A handout photograph made available by Univision Florida Central showing a view of the general scene following a shooting at Pulse Nightclub in Orlando, June 12, 2016. (EPA/UNIVISION FLORIDA CENTRAL)

Shooting rampage at Florida nightclub

An injured man is escorted out of the Pulse nightclub after a shooting rampage, Sunday morning June 12, 2016, in Orlando, Fla. (AP Photo/Steven Fernandez)

Shooting rampage at Florida nightclub

A handout photograph made available by Univision Florida Central showing a view of the general scene of a shooting at Pulse Nightclub in Orlando, Florida, June 12, 2016. Orlando Police state there are multiple injuries with reports stating that the attacker is still inside the club and has taken hostages. (EPA/UNIVISION FLORIDA CENTRAL)

Shooting rampage at Florida nightclub

Bystanders wait down the street from a multiple shooting at the Pulse nightclub in Orlando, Fla.,June 12, 2016. (AP Photo/Phelan M. Ebenhack)

Shooting rampage at Florida nightclub

Police cars and emergency vehicles surround the Pulse Orlando nightclub, the scene of a fatal shooting, in Orlando, Fla., Sunday, June 12, 2016. (AP Photo/Phelan M. Ebenhack)

Shooting rampage at Florida nightclub

Emergency personnel wait with stretchers at the emergency entrance to Orlando Regional Medical Center hospital for the arrival of patients from the scene of a fatal shooting at Pulse Orlando nightclub in Orlando, Fla., Sunday, June 12, 2016. (AP Photo/Phelan M. Ebenhack)

Shooting rampage at Florida nightclub

Orange County Mayor Teresa Jacobs, right, is briefed after arriving to the scene of a fatal shooting at Pulse Orlando nightclub in Orlando, Fla., Sunday, June 12, 2016. (AP Photo/Phelan M. Ebenhack)

Shooting rampage at Florida nightclub

Police lock down Orange Avenue around Pulse nightclub, where people were killed by a gunman in a shooting rampage in Orlando, Florida June 12, 2016. (REUTERS/Kevin Kolczynski)

Shooting rampage at Florida nightclub

A police officer stands guard outside the Orlando Regional Medical Center hospital after a fatal shooting at a nearby Pulse Orlando nightclub in Orlando, Fla., Sunday, June 12, 2016. (AP Photo/Phelan M. Ebenhack)

Shooting rampage at Florida nightclub

Orange County Sheriff’s Department SWAT members arrive to a fatal shooting at Pulse Orlando nightclub in Orlando, Fla., Sunday, June 12, 2016. (AP Photo/Phelan M. Ebenhack)

Shooting rampage at Florida nightclub

People gather as police conduct questioning near Pulse nightclub, where people were killed by a gunman in a shooting rampage in Orlando, Florida June 12, 2016. (REUTERS/Kevin Kolczynski)

Shooting rampage at Florida nightclub

Dr. Michael Cheatham, chief surgeon of the Orlando Health Regional Medical Center hospital, addresses reporters during a news conference after a shooting involving multiple fatalities at a nightclub in Orlando, Fla., Sunday, June 12, 2016. Watching are Orange County Sheriff Jerry Demings, second from right, and Orlando Mayor Buddy Dyer. (AP Photo/Phelan M. Ebenhack)

Shooting rampage at Florida nightclub

Police lock down Orange Avenue around Pulse nightclub, where people were killed by a gunman in a shooting rampage in Orlando, Florida June 12, 2016. (REUTERS/Kevin Kolczynski)

Shooting rampage at Florida nightclub

Orlando Police Chief John Mina, center, addresses reporters during a news conference after a shooting involving multiple fatalities at a nightclub in Orlando, Fla., Sunday, June 12, 2016. (AP Photo/Phelan M. Ebenhack)

Shooting rampage at Florida nightclub

Friends and family members embrace outside the Orlando Police Headquarters during the investigation of a shooting at the Pulse nightclub, where people were killed by a gunman, in Orlando, June 12, 2016. (REUTERS/Steve Nesius)

Shooting rampage at Florida nightclub

Police lock down Orange Avenue around Pulse nightclub, where people were killed by a gunman in a shooting rampage in Orlando, Florida June 12, 2016. (REUTERS/Kevin Kolczynski)

Shooting rampage at Florida nightclub

Police and rescue officers monitor the scene of a shooting at Pulse nightclub in Orlando, June 12, 2016. (EPA/CRISTOBAL HERRERA)

Shooting rampage at Florida nightclub

Friends and family members embrace outside the Orlando Police Headquarters during the investigation of a shooting at the Pulse nightclub, where people were killed by a gunman, in Orlando, June 12, 2016.

Shooting rampage at Florida nightclub

Police and rescue officers monitor the scene of a shooting at Pulse nightclub in Orlando, June 12, 2016. (EPA/CRISTOBAL HERRERA)

Shooting rampage at Florida nightclub

A handout photograph posted by the Orlando Police Department on Twitter with the words, “Pulse shooting: In hail of gunfire in which suspect was killed, OPD officer was hit. Kevlar helmet saved his life”, in reference to the operation against a gun man inside Pulse night club in Orlando, Florida, June 12, 2016. (Orlando Police Department/Handout via REUTERS)

Shooting rampage at Florida nightclub

Potential blood donors line up outside the oneblood facility on Beach Blvd. In Jacksonville, Fla., June 12, 2016, to help the victims from the shooting at a nightclub in Orlando. (Bob Self/The Florida Times-Union via AP)

Shooting rampage at Florida nightclub

Authorities have identified the gunman in Sunday’s mass shooting that left at least 50 dead in Orlando, Florida as Omar Mateen. (WABC)

Shooting rampage at Florida nightclub

An undated photo from a social media account of Omar Mateen, who Orlando Police have identified as the suspect in the mass shooting at a gay nighclub in Orlando, Fla., June 12, 2016. (Omar Mateen via Myspace/Handout via REUTERS)

Shooting rampage at Florida nightclub

Hundreds of community members line up outside a clinic to donate blood after an early morning shooting attack at a gay nightclub in Orlando, Florida, June 12, 2016. (REUTERS/Steve Nesius)

Shooting rampage at Florida nightclub

People hold a vigil outside the Orlando Regional Medical Center in the aftermath of a mass shooting in Orlando, Florida, on June 12, 2016. (GREGG NEWTON/AFP/Getty Images)

Shooting rampage at Florida nightclub

Investigators from the office of the medical examiner investigate on the west side of Pulse nightclub where a gunman opened fire on Sunday morning, June 12, 2016, in Orlando, Fla. (Doug Clifford/The Tampa Bay Times via AP)

Shooting rampage at Florida nightclub

Volunteers Clinton Grubb (L), Brittani Acuff (C) and others gather at The Center, a GLBT organization, to provide assistance and counseling to the community after an early morning shooting attack at a gay nightclub in Orlando, June 12, 2016. (REUTERS/Steve Nesius)

Shooting rampage at Florida nightclub

Terry DeCarlo, executive director of the LGBT Center of Central Florida, right, is comforted by an Orlando Police officer after a shooting involving multiple fatalities at a nightclub in Orlando, Fla., June 12, 2016. (AP Photo/Phelan M. Ebenhack)

Shooting rampage at Florida nightclub

Florida Gov. Rick Scott arrives on the scene near the nightclub where a mass shooting occured in Orlando, Fla., June 12, 2016. (Joe Burbank/Orlando Sentinel via AP)

Shooting rampage at Florida nightclub

Bomb disposal officers check for bombs at an apartment complex of a suspect linked to the fatal shootings at an Orlando nightclub, Sunday, June 12, 2016, in Fort Pierce, Fla. (AP Photo/Alan Diaz)

Shooting rampage at Florida nightclub

Law enforcement officials work at the scene of the Pulse Orlando nightclub following a fatal shooting Sunday, June 12, 2016, in Orlando, Fla. (AP Photo/Chris O’Meara)

Shooting rampage at Florida nightclub

Two bodies of victims arrive at the Orlando Medical Examiner’s Office, Sunday, June 12, 2016, in Orlando, Fla. (AP Photo/Alan Diaz)

Shooting rampage at Florida nightclub

Orlando Mayor Buddy Dyer, center right, and Orlando Police Chief John Mina, center left, arrive to a news conference after a fatal shooting at Pulse Orlando nightclub in Orlando, Fla., June 12, 2016. (AP Photo/Phelan M. Ebenhack)

Shooting rampage at Florida nightclub

Gary Wilford, of Orlando, Fla., weeps near the scene of a mass shooting, June 12, 2016, in Orlando, Fla. (AP Photo/Tamara Lush)

Shooting rampage at Florida nightclub

Hundreds of community members line up outside a clinic to donate blood after an early morning shooting attack at a gay nightclub in Orlando, Florida, June 12, 2016. (REUTERS/Steve Nesius)