A moped rider was critically injured in a hit-and-run in Waimanalo Saturday.

Honolulu police said a sedan was traveling west on Kalanianaole Highway and rear-ended the moped rider, 36, at about 7:30 p.m. The rider was thrown onto the pavement upon impact.

Police said the rider sustained head and bodily injuries and was taken in critical condition to a hospital. He was not wearing a helmet at the time of the collision.

Police noted the sedan driver did not stop to render aid and continued westbound on the highway.

Speed was a factor on the part of the sedan, police added. It’s unknown whether alcohol or drugs were factors.

Anyone who witnessed the crash is asked to call the Honolulu Police Department’s Traffic Division at 808-723-3413.