UPDATE - US: About 20 dead, 42 injured in Orlando club shooting

UPDATES THROUGHOUT

NEW YORK (AA) - A shooting at a gay nightclub in Orlando, Florida, in the U.S. early Sunday morning left "around 20 people" dead and at least 42 injured, police have confirmed.

The attack at Pulse Club took place at around 2 a.m. (0600GMT), Orlando police chief John Mina told reporters at a news briefing on Sunday morning.

Mina said the police decided to "rescue hostages that were in there" at 5 a.m. (0900GMT).

He said nine officers entered the club and engaged the attacker, who carried an assault rifle, a handgun, and a “suspicious device” police officers have yet to identify. The shooter was killed and one officer was injured in the shoot-out, during which 30 people were rescued.

Local TV station 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 car, police said.

There is no official information on the identity of the suspect, but an FBI official at the briefing said the agency had “suggestions” that the individual might have “leanings toward” radical Islam.

The area remains under police lockdown. Mina said dead bodies were still inside the club, while adding there was no indication of continued threat to the community. WESH reported that as many as 300 people could have been 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 their official Twitter account, described it as a “mass casualty situation”.

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

Orlando mayor Buddy Dyer described the incident as a "horrific crime" that will have a "lasting effect" on the local community, while an Orange County sheriff at the briefing said the shooting was a "domestic terror incident".

Pulse calls itself “Orlando’s premier gay nightclub”. Police are looking into whether the incident was a hate crime against the LGBT community.