Four people were injured, two critically, in traffic accidents last night in Wahiawa and Kailua.

A woman was critically injured and two people suffered serious injuries in a head-on collision on Kamehameha Highway just outside Wahiawa.

The accident was reported at 6:43 p.m. near Helemano Plantation. Two cars collided on the bridge near Poamoho Farms, police said.

An 18-year-old woman in one car was critically injured, said Bryan Cheplic, spokesman for the city Emergency Services Department. A woman in the other car and a boy in his teens were seriously injured, Cheplic said.

In Kailua, a man was injured when he was struck by a car as he crossed Kailua Road fronting Bank of Hawaii shortly after 8:30 p.m.

The man, described as in his 50s, was taken to The Queen's Medical Center in critical condition, police said.