Six people are still in intensive care after the Orlando shooting - as one victim said he escaped death when the killer aimed at his head but hit his hand.

Medics described how they saw the "full gamete of wounds" after Sunday's attack that left 49 dead - injuries to the extremities, the abdomen and large soft tissue wounds.

One victim - appearing alongside doctors at Orlando Regional Medical Centre - said he was shot in the leg and trampled on when people fled as the massacre began.

"He's shooting everyone that's already dead on the floor...I could see him shooting everyone...I look over and he shoots the girl next to me," said Angel Colon.

"I don't know how, but by the glory of God he shoots toward my head, but it hits my hand."

"And I'm there laying down and thinking, I'm next, I'm dead."

Mr Colon was also shot in the hip as killer Omar Mateen continued hunting down victims in the Pulse nightclub with "bodies everywhere."

"He is shooting everybody that is already dead on the floor, making sure they are dead," he told reporters.

"I was able to peek over and I can just see him shooting everyone."

Mr Colon described the deafening gun battle as police exchanged fire with Mateen, and said a police officer was eventually able to drag him to safety across a floor of broken glass.

"I am looking up and some cop that I wish I could remember his face or his name, because to this day I'm grateful, he looks at me and makes sure I am alive."

"He grabs my hand and he says, this is the only way I can take you out."

"I couldn't walk. So he starts to drag me out across the room to the Wendy's. I said, please carry me, because I'm in pain right now".

Dr Will Havron told reporters the night was a "surreal experience" with dozens of patients desperately needing emergency treatment.

It comes amid reports that Mateen had been seen at least a dozen times at the gay club where he carried out the killings, with some men saying he has also messaged them on gay chat apps.

Earlier, Mateen's father claimed the attack could have been prevented if the club had better security.

Seddique Mateen said he shares the grief of the victims' families, and that religion had nothing to do with his son's actions.

But he said the nightclub must share responsibility for the worst mass shooting in US history, which killed 49 people and injured 53 others.

Mr Mateen said: "That club should have had good security. The club, (with) 300 or 400 people...coming - they should have good security. If there was good security, he wouldn't have had this opportunity."

"Why the law enforcement team was so late - they should have neutralised him quick...This should not have happened."

He added: "Obviously if (the club) had that kind of experience, they should have had better security and after this any club should have security. They should protect people that come in the club."