Oslo - A lightning bolt struck 91 auto racing fans at a racetrack in Norway Sunday, and 45 people were taken to hospital with minor burns, police said.

"No one was seriously injured," police officer Hans Eng told the Associated Press. "But some of them will stay in the hospital for observation."

The lightning hit a hill where spectators at the rallycross were sitting. Rallycross is a form of sprint-style automobile racing on a closed circuit.

The race, a national championship, was called off after the incident.

Eng said 16 ambulances and three medical helicopters were brought to the scene at Flisa, about eight kilometers from the Swedish border.

The injured fans were taken to four different hospitals.

"I've never seen anything like it; spectators fell off their seats," a witness, Roar Bringaker, was quoted as saying on the Web site of Norwegian paper Verdens Gang. "People got scared and ran. It was chaotic."

Even Wiger, another spectator, went to the racetrack with his 14-year-old son and some friends.

"It was a raining and suddenly the lightning hit the stand," he was quoted as saying to the Norwegian News Agency NTB. "We all tried to get down from the hill. Many screamed and cried. The situation was dramatic. I've never experienced anything similar."

The thunderstorm knocked out telephone service in the area, police said.