The rider and passenger on each bike were thrown to the pavement after the 1:15 p.m. collision, according to Sgt. Peter Fulton of the Windham Police Department. Police are not releasing the names of those injured until family members can be notified, he said.

They were among 120 motorcycles taking part in the fifth annual motorcycle run organized by non-profit group Bikers Against Breast Cancer, Maine. The ride which began Saturday morning in Buxton.

“All I know is that four people are in the hospital,” distraught organizer Gordon Morse said Saturday afternoon. “Try to do something good and a bad thing happened.”

The motorcycle drivers had been slowing down in traffic when the accident occurred, Fulton said.

“Some of the injuries involved are considered to be critical at this time,” he wrote in the news release.

Fulton said it appeared at least some of the injured people had not been wearing helmets. Police don’t think speed was a factor, but the accident remains under investigation, he said. A reconstruction is being done by the Windham Police Department accident investigation unit, he said, and charges may be issued pending the investigation.

Fulton said that police are asking any ride participant who saw the accident to contact Officer Rob Hunt at 892-2525.