Orlando shooting: Father of gunman Omar Mateen apologises and says attack had 'nothing to do with religion'

Father claims his son became angry when he saw two men kissing in Miami several months ago

The gunman has been identified as Omar Mateen, a 29-year-old from Fort Pierce in Florida (AP)

The father of the man named as responsible for the biggest mass shooting in US history says the massacre at an LGBT nightclub in Orlando "has nothing to do with religion".

Omar Mateen's father claimed his son had became angry after seeing two gay people kissing in Miami, and he believed the incident was relevant to the attack.

At least 50 people have been killed and 53 injured in a “terrorist” attack on a gay nightclub called Pulse in the early hours of Sunday morning. Florida authorities have declared a state of emergency.

The gunman has been identified as Omar Mateen, a 29-year-old from Fort Pierce in Florida. Mr Mateen’s family is from Afghanistan and he is believed to have been born in the US.

His father, Mir Seddique, told NBC News his son apparently became angry when he saw two men kissing in Miami several months ago. He said he believed this could be linked to the shooting.

“We are apologising for the whole incident,” his father said. “We weren’t aware of any action he was taking. We are in shock, like the whole country.”

Orlando's mayor, Buddy Dyer, announced the casualties at a press conference this morning.

Many of those wounded remain in hospital and six additional trauma surgeons have been rushed in to Orlando, officials say.

An urgent appeal has been issued for blood donors, and there has been an extraordinary response from the local community.