A suspected terrorist shooting at an LGBT nightclub in Orlando has left at least 20 people dead, police have confirmed, adding that the attacker had been killed following a hostage situation at the club.

Shots were fired at the Pulse Club, in the early hours of Sunday. Staff at the venue posted on Facebook: “Everyone get out of pulse and keep running” and there were quickly reports on social media of an ongoing attack.

Orlando police said the shooting was being treated as an “act of domestic terrorism” and had resulted in mass casualties, urging people to stay away from the area.

Police said a number of people had been killed in the attack – in the “vicinity of 20” – but refused to give an exact death toll. They added that 42 people had been taken to hospital, including one police officer who had been shot in the head, but whose “life had been saved by his Kevlar helmet”. They confirmed the gunman was armed with an assault rifle, handgun and “some kind of device”.

In a press conference on Sunday morning, an FBI spokesman said investigators believed the attacker may have had extremist beliefs, and would consider possible links to Isis, but cautioned they were pursuing multiple leads.

An explosion was heard at the club at about 5am local time, which police said was a “distractionary device” used as part of the rescue mission to get to the hostages. The explosion caused some panic on the ground, which led to Orlando police tweeting to say it had been a “controlled explosion” and warning media about reporting inaccuracies.

Police confirmed the incident began at 2am when the gunman started firing and an officer on duty at the club exchanged shots with him. They said it then descended into a “hostage situation”. The situation was resolved three hours later when a Swat team stormed the nightclub after receiving messages from club patrons who were hiding in the club while the gunman was still at large.

“A little after 0500 hours we made a decision to go in and conduct a rescue, we were being contacted by people in the bathroom, about 15 people, our biggest concern was future loss of life,” said John Mina, the chief of police.

Several explosives and an armoured vehicle were used to break through a wall of the nightclub and rescue approximately 30 hostages. The suspect was shot by a police officer during this intervention.

(The Guardian)