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A near-naked gunman has killed at least four people at a Waffle House restaurant near Nashville, Tennessee before fleeing after a patron wrestled the semi-automatic AR-15 rifle from his hands.
The suspected shooter, identified by authorities as Travis Reinking, 29, was still at large and murder warrants were being issued for him, the Metropolitan Nashville Police said.
The gunman's vehicle was registered to him and a shirtless man wearing pants believed to be Mr Reinking was spotted in woods nearby, police said.
The gunman, who was naked but for a green jacket, first shot and killed two people in the carpark of the restaurant shortly before 3:30am (local time).
He then entered the restaurant and opened fire, police said, killing one patron and injuring another, who later died.
One diner, named by local media as James Shaw Junior, 29, who had hidden, dashed out and pulled the rifle from the gunman.
"The shots had stopped so he decided to rush the gunman, actually wrestled that assault rifle away, tossed it over the counter and, at that point, the gunman fled," said police spokesman Don Aaron.
Mr Shaw's fast actions were credited with saving lives, but in an interview with the Tennessean newspaper he dismissed the idea that he was hero.
"It feels selfish," said Mr Shaw, who added that he had been getting a snack with friends after a house party.
"I was just trying to get myself out. I saw the opportunity and pretty much took it."
Mr Shaw suffered non-life-threatening injuries.
As the shooter ran off he discarded the jacket, which contained additional ammunition, according to police.
Police cautioned that the suspect was to be considered still armed and extremely dangerous.