A car smashed into a guardrail on a straight stretch of the Kanetsu Expressway in Kodama, Saitama Prefecture, in the rain early Monday, killing four of its five male occupants, highway police said.

The driver, Kazuaki Yuzawa, 20, of Maebashi, Gunma Prefecture, suffered head injuries.

Killed were Keita Harada, 19, Hayata Hirokawa, 17, and Hisayuki Yamane, 17, all of Maebashi. The fourth victim has not been identified.

According to police, marks on the road indicate the car rolled over and the back of the vehicle hit the barrier.

The accident occurred on a straight section of the expressway, which links Tokyo and Niigata, and no other vehicle was involved, police said, adding it was raining at the time of the accident. The speed limit during rain is 80 kph.

A motorist contacted prefectural police about the wrecked vehicle at about 7:25 a.m.

Police said the car had apparently been traveling in the direction of Tokyo.