A 67-year-old Buxton man suffered life-threatening injuries in a motorcycle accident Saturday on Riverside Street in Portland, police said Sunday.

David York was operating his motorcycle at 3:09 p.m. when it crashed near 536 Riverside St., police said.

He was taken to Maine Medical Center, where he was listed in serious condition Sunday night.

The accident is being investigated.

Anyone with information about the accident is asked to call police at 874-8532 or 874-8575.