Belgian cyclist Yannick Eijssen has been forced out of the Tour of Beijing after an accident apparently caused by a billboard loosened by a low-flying helicopter.

The accident occurred Friday during the third stage of the race around the Chinese capital.

The 22-year-old Eijssen, who rides for Team BMC Racing, suffered a fracture to a small bone beneath his nose in what race organizers called a "freak accident."

A notice on the event's official website said organizers were investigating reports that a television helicopter forced billboards onto the course. A television motorcycle also was involved in the accident, but no other riders were affected.

The race ends Sunday at the Bird's Nest stadium in northern Beijing.