Roubaix, France ? Three spectators were seriously injured Sunday when a motorcycle crashed into fans watching the Paris-Roubaix cycling race, a one-day classic won by Belgium’s Tom Boonen.

Three people were taken by helicopter to hospitals in Lille and Valenciennes for further scans, two for abdominal injuries and a woman who was briefly knocked unconscious, said Philippe Sudres, a spokesman for race organizer Amaury Sport Organization.

“Doctors do not think their (lives) are in danger, but we have to wait for the results,” Sudres said.

About a dozen others needed medical treatment, Sudres said.

The motorcycle belonged to race organizers to provide regular time checks for riders, he said. It appeared to lose control and swerved sideways into the side of the road.