Two people died and two others were seriously injured following a head-on collision involving two vehicles Monday afternoon along Kamehameha Highway near Gunstock Ranch, according to Honolulu police.

Honolulu police told reporters that they have opened a negligent homicide and manslaughter case connected to the crash fronting Malaekahana State Recreation Area.

At about 1:05 p.m. Monday, police said a 27-year-old man was allegedly driving a Ford truck heading northbound on Kamehahemha Highway and driving recklessly, weaving in and out of traffic to bypass vehicles and eventually crossing the centerline. Just before 1:30 p.m., the driver of the truck apparently collided head-on with a Hyundai sedan traveling in the opposite direction, police said. That prompted the closure of the highway in both directions for several hours.

The driver of the Ford was taken to a hospital in serious condition.

A 55-year-old woman who was driving the Hyundai sedan was taken to an area hospital where she later died from her injuries. A 62-year-old man who was a rear-seat passenger in the sedan was pronounced dead at the scene. Their identities have not been released. A 30-year-old woman who was in the front passenger seat was taken to a hospital in critical condition.

Police said speed appears to be a factor in the collision, but drugs and alcohol do not appear to be contributing factors.

This marked the 31st and 32nd traffic fatalities on Oahu this year compared to 33 at the same time last year.

The investigation is ongoing.