The full horror of a mass shooting at an LGBT nightclub that left 50 people dead and 53 wounded is emerging, as witnesses and relatives of the victims reveal the last communications they received from their loved ones as they were held hostage inside the venue.

Mina Justice, the mother of one of the victims, shared the heartbreaking texts she received from her son Eddie Justice from inside the Pulse nightclub in the early hours of Sunday morning (12 June). He has been confirmed among the dead victims of the shooting.

The 30-year-old texted his mother, in order to alert authorities as a lone gunman began shooting inside the club at around 2am. "Mommy I love you. In the club they shooting," he wrote. He told her he and other revellers had run into the women's toilets in a bid to escape the gunman, adding "he's coming".

"Call them momm (sic). Now. I'm tell I'm bathroom. He's coming. I'm gonna die," Eddie wrote. The next text said: 'He has us, and he's in here with us."

"That was the last conversation," Mina Justice said.

She told WOFL that her son had initially called her and the terror was evident as he spoke to her. "I think it's all of them in the bathroom. I could hear a lot of people crying," she told the station, adding that her son was "just afraid he's gonna die".

She said that he hung up the phone as the gunman approached them. "[Eddie] said, 'He has us and he's fixin to kill us.' That was it.'"

Pulse nightclub shooting
Eddie Justice sent a final tragic text to his mother as he was held hostage inside the bathroom by the gunman during a mass shooting, which left over 50 people dead, at Pulse Nightclub in Orlando, Florida, on June 12, 2016. wftv

The gunman - who has since been identified as American-Afghan Omar Mateen - went on a murderous rampage, armed with an handgun and a semi automatic rifle. Eyewitnesses who were inside the club have recounted the ordeal as they heard a volley of shots and saw people fall to the ground around them

Javer Antonetti, 53, was near the back of the nighclub when he heard gunfire. He told the Orlando Sentinel: "There were so many (shots), at least 40. 'I saw two guys and it was constant, like 'pow, pow, pow.''"

Police seen outside Pulse, Orlando
Police officers seen outside Pulse nightclub where at least 50 died in a mass shooting on Sunday, 12 June, 2016. Getty

Christopher Hansen who was in the VIP lounge said he saw injured people spilling out of the club as the shooting continued inside Mail Online reports. "I was thinking, are you kidding me? So I just dropped down. I just said please, please, please, I want to make it out. And when I did, I saw people shot. I saw blood."

There were 320 people in the club at the time of the shooting. Many were able to escape due to the quick actions of a bouncer who knocked down a partition between the club and a back stage area. As the incident unfolded, the Pulse nightclub posted a message on its Facebook page reading: "Everyone get out of Pulse and keep running."

A gunman killed 50 people and injured 53 in a crowded gay nightclub in Orlando
A gunman killed 50 people and injured 53 in a crowded gay nightclub in Orlando, Florida, before being shot dead by police on June 12, 2016. Reuters

The gunman engaged in an exchange of gunfire with an officer at the scene before going back into the club where he held people hostage. After a three-hour stand-off, a SWAT team stormed the premises to rescue the hostages. Mateen was killed in the ensuing gunfight.

As speculation mounts as to the motive of the shooter, a US citizen of Afghan descent authorities have described the incident as an "an act of terrorism" and a mass killing on an unprecedented scale. In a press conference President Obama said it was "an act or hate and an act of terror."

It has been reported that prior to the killings, Mateen pledged his allegiance to Islamic State. Authorities are looking to determine whether the shooter was a lone wolf.

As the tragic stories of the victim's final moments emerge, the public are turning to social media to express their shock and outrage at what is the worst mass shooting in US history.