Police say speed was a factor in a crash on Kamehameha Highway last night that sent four people to the hospital.

A silver 2005 Jeep sports utility vehicle Haleiwa-bound on Kamehameha Highway veered into oncoming traffic near Helemano Military Reservation and hit a white 2004 Toyota sedan at about 6:30 p.m., police said.

Paramedics took a woman in her 20s to the hospital in critical condition and three others — a man and a woman in their 20s and a 29-year-old woman — to the hospital in serious condition, officials said.

The Jeep, driven by a 36-year-old Wahiawa man, skidded into a ditch and overturned. The Jeep’s driver was treated at the scene and arrested for negligent injury, police said.

Paramedics took the 20-year-old driver of the Toyota and her passengers — a 24-year-old woman, a 25-year-old woman and a man in his 20s — to the hospital.

Police said the Toyota driver, front seat passenger and male rear seat passenger were in serious condition. A woman in the back seat, who was not wearing a seat belt, was in critical condition, but improved to serious.

The driver and front seat passengers in both vehicles were wearing seat belts and airbags deployed in both vehicles, police said.

Police closed Kamehameha Highway until about 10:30 p.m. while they investigated the crash.