Footage and texts from the nightclub attack in Orlando have captured scenes of heavy gunfire inside the Pulse venue and the aftermath of the worst shooting in recent US history.

Gunman Omar Mateen opened fire inside Pulse nightclub at around 2am, killing 49 people and injuring 53 others before being shot dead by police.

Inside the nightclub, which was hosting a night of dancing and drag acts, revellers attempted to flee as the gunshots sounded, with many barricading themselves in toilets in an attempt to escape the shooter.

One man, 30-year-old Eddie Jamoldroy Justice, texted his mother Mina Justice throughout the attack, writing: "Mommy I love you. In the club they are shooting."

He ran into the lavatories with others, who attempted to hide from the gunman.

"Call them momm (sic). Now. I'm in the bathroom. He's coming. I'm gonna die," Justice wrote.

The next text said: 'He has us, and he's in here with us."

"That was the last conversation," Mina Justice said. Her son was later confirmed as one of the 49 victims of the massacre.

Snapchat video captures moment of shooting at Pulse nightclub IBTimes UK

Another victim, 25-year-old Amanda Alvear, sent her friend Snapchat videos throughout the evening, culminating in one that included gunshots in the background. Her siblings confirmed today she had been killed in the shooting.

The nightclub's Facebook page sent a chilling message as the shooter opened fire at around 2am, telling people: "Everyone get out of Pulse and keep running".

Twitter/lakecitymedman via Storyful

People used the club's Facebook page to keep up to date on what was happening to their loved ones who had visited Pulse that evening. One woman, Lilbia Carmen wrote: "Nothing yet. My daughter is in there.

"Please keep praying for them... She's waiting for cops to be able to come out. I was on the fone and all I hear is shot guns (sic)."

The woman later wrote that her daughter had managed to get out of the club to safety.

Some of the people who did not manage to flee as Mateen opened fire were found by the shooter and taken hostage until the police shot him at around 5am.

YouTube/David Ward via Storyful

Neighbours of the club took video footage capturing the sounds of gunshots ringing out into the night as the attack unfolded.

A man whose friend was shot in the attack shared footage of the authorities working outside the club helping those who had been wounded in the attacks, while the Orlando Police Department released a video of the city's mayor Buddy Dyer telling crowds "we will not be defined by this act of terror".

One resident who lived nearby took several images of police and medical professionals inspecting the scene the day after the attack, with the bodies of the people killed enjoying a night out being removed from the club on Sunday.

YouTube/David Ward via Storyful