Scene of Orlando gay club shooting
Scene of Orlando gay club shooting Reuters

A Muslim gunman has killed at least 50 people and left 53 others wounded in a shooting spree at a gay nightclub in Orlando, Florida. In what President Barack Obama has since described as an act of terror, the killer - named by police as Omar Mateen - stormed the Pulse Club and took hostages before being shot dead by security forces.

Florida governor Rick Scott has already said the murder - which is the worse shooting spree in American history - was "clearly an act of terror".

The casualty count surpasses that of the Virginia Tech massacre in 2007, in which 32 people were murdered by a mentally-deranged gunman. Until Sunday's attack, that was considered the worse gun massacre in US history.

It is not yet known if Mateen was acting alone or as part of a larger terrorist plot. However, NBC news reported that Mateen called police before the attack and swore allegiance to the Islamic State terrorist group (ISIS). ISIS has since taken credit for the attack.

But the murderer's father Mir Seddique told the news channel that the attack had nothing to do with religion, though he went on to speculate that it was triggered by the sight of a gay couple kissing in Miami.

Mateen, a Muslim-American of Afghan descent, was not on any terror watch list but did have a criminal record.

According to Orlando Police Chief John Mina the attack began at 2:00 a.m. local time, with an exchange of fire with a police officer who worked at the club either inside or outside the venue itself.

Soon after a "hostage situation" commenced, and three hours after the start of the attack police stormed the club and killed the gunman.

"Our Swat officers exchanged gunfire with the suspect, the suspect is dead," he said. "He appeared to be carrying an assault-type rifle and a handgun, and had some type of device on him."

Police bomb disposal units were also at the scene to diffuse the suspected bomb and to search the scene for other possible explosives.