Four people were killed and four others were injured after a semi-nude gunman opened fire at a Waffle House restaurant near Nashville early Sunday, police said. The shooter remained at large Sunday morning.

The gunman, naked except for a green jacket, got out of his car at around 3:23 a.m. local time (4:23 a.m. ET) Sunday morning and shot two people outside the restaurant with "an assault-type rifle," killing them both, Metro Nashville Police Department Spokesman Don Aaron said at a news conference.

He then went inside the Waffle House and continued firing, killing another person. Authorities later confirmed a fourth person had died at a hospital.

A 29-year-old restaurant patron managed to wrestle the firearm away from the shooter, Aaron said.

"He reported that he saw the gunman looking at his rifle, at that point the shots had stopped, so he decided to rush the gunman, actually wrestled that assault rifle away, tossed it over the counter, at that point the gunman then fled," he said.

"As he was in the Waffle House, he was wearing only a green jacket — no pants, no shirt, just a green jacket," he said. The jacket had ammunition cartridges in it, he later added.

 The suspect shed the green jacket while fleeing the scene, Aaron said.

Authorities named Travis Reinking, 29, of Morton, Illinois, as a person of interest. They say the vehicle the gunman arrived in was registered to him. Later Sunday, police said they were drafting murder warrants against Reinking.

"We don't know what he was doing in Nashville," Aaron said. Both federal and state authorities "have knowledge of Reinking due to previous interactions."

"Again, why he is in Nashville and what prompted this this morning has not been determined," Aaron said.

Police said the man believed to be Reinking was last seen in a wooded area near an apartment complex not far from the scene of the shooting and that he had put on a pair of pants since fleeing the shooting. The man was seen wearing black pants and no shirt or jacket.

Police are now trying to locate him and are asking anyone who sees him to contact them immediately.