A horrific scene unfolded at a nightclub in Columbus, Ohio Wednesday night when a man climbed on stage and started shooting at members of a rock band and into the crowd, killing four people. Police later shot the gunman dead.

Officials say the man was targeting the band Damageplan, whose members were performing on stage when the attack happened. The gunman shot guitarist "Dimebag" Darrell Abbott five or six times at point-blank range.

Police released the names of three victims. They say Abbott was killed along with two other men -- Nathan Bray and Erin Halk. A fourth victim has not been identified.

The gunman had a hostage in a headlock and appeared to be preparing to kill him when a police officer who responded to a call for help fired, police spokesman Sgt. Brent Mull said. The hostage escaped uninjured.

"The officer engaged him in gunfire at that point and probably saved numerous lives from his actions," Mull said.

"If the officer wasn't as close as he was, I think this would have been a lot worse,'' he said. "It was a chaotic scene, just a horrific scene.''

The gunman was identified as 25-year-old Nathan Gale who lives in the Marysville area, near Columbus. The motive for the shooting remains unclear, and it's not known whether Gale had any connection to the band.

Darrell Abbott was an original member of the thrash rock group Pantera, a popular heavy metal bands of the early 1990s.

One witness said the gunman was standing about 10 metres away when he saw the man walk onstage followed by a bouncer and a second club employee.

The gunman reportedly climbed onto the stage, where he shot Abbott five or six times at close range. Then he shot a bouncer who pulled him off Abbott. A police spokesman said the gunman then started firing into the crowd.

One of the audience members said she initially thought the shooting was part of the show.

"I just saw the guitarist fall down, and we decided to get out of there," she told the Associated Press.

The deaths shook the heavy-metal music industry, including Ozzy Osbourne, who often toured with Pantera..

"I'm absolutely beside myself with grief. I can't for the life of me understand why someone would do this," said Osbourne.