WINDHAM — One man remained in critical condition Sunday after two motorcycles collided the previous day during a charity ride.

Ricky Morse, 28, of Buxton was the most seriously injured, according to Windham Police Sgt. Peter Fulton. He and passenger Kaitlin Knight, 24, had been on his 2001 Yamaha on the River Road in Windham when it collided with a motorcycle ridden by Jon Swan, 54, and his wife, Debora Swan, no age given, both of Bethel.

They were among 120 motorcycles and riders taking part in the fifth annual motorcycle run organized by nonprofit group Bikers Against Breast Cancer, Maine, which began Saturday morning in Buxton.

The motorcycles were slowing in traffic when the accident occurred, according to a news release issued Sunday by Fulton. After the collision, Morse, Knight and the Swans all were thrown to the pavement. According to police, Debora Swan was wearing a helmet. On Saturday, Fulton had said that some of the riders had not been wearing their helmets.

Police did not share specific information about the injuries.

Speed does not appear to be a factor in the accident, Fulton said in the news release, adding that charges may be issued pending investigation. The scene is being reconstructed by the Windham Police Department accident investigation unit, and any ride participant that witnessed the crash is asked to contact Officer Rob Hunt at 892-2525.