A 74-year-old bicyclist was seriously injured after he was struck by a vehicle in a hit-and-run in Ewa Beach Sunday.

The collision occurred on Fort Weaver Road near the Keaunui Drive intersection at about 6:15 p.m.

Honolulu police said the bicyclist was traveling northbound on Fort Weaver Road when he was struck from behind by an unknown motorist.

The motorist fled the scene and continued northbound on the road, police said.

The vehicle that struck the bicyclist was described as a possible light-colored passenger van with damage to the front area.

Police said the bicyclist was taken in serious condition to a hospital. He was not wearing a helmet at the time of the collision.

It’s unknown at this time whether speed, drugs or alcohol were factors.

Anyone with information on the hit-and-run is asked to contact the Honolulu Police Department’s Traffic Division at 808-723-3413.