Honolulu police are searching for the suspect in a hit-and-run collision in Waipahu that sent a motorcyclist to the hospital in serious condition.

Police said at about 7:49 p.m. Sunday, a 21-year-old motorcyclist was reportedly exiting the H-1 freeway onto H-2 northbound when an unidentified motorist rear-ended him. The motorist continued northbound without stopping to render aid or provide information.

The motorcyclist was ejected onto the roadway, and taken by Honolulu Emergency Medical Services to a hospital in serious condition. He was wearing a helmet.

No description of the suspect nor the vehicle was provided.

Police said it remains unknown if speed, drugs, or alcohol are contributing factors. The investigation is ongoing.

Anyone with information is asked to contact the Honolulu Police Department Traffic Division at 808-723-3413.