Honolulu police closed Kalanianaole Highway in both directions between Hihimanu Street and Inoaole Street in Waimanalo for about an hour this morning after a head-on collision.
The accident was reported at 6:40 a.m. and the highway reopened at about 7:30 a.m.
A Honolulu Fire Department spokesman said three people were injured, a man and a child in one vehicle and a woman in the second vehicle. An Emergency Medical Services supervisor said the victims went to the hospital in serious condition.
No other details were immediately available.