A 6-year-old boy died and 11 others were injured Friday morning after a pickup truck tipped over following a collision with two other vehicles and hit elementary school children walking to school on a street in Yokohama, the local fire department said.

Police said they are planning to arrest the 87-year-old driver of the truck on suspicion of professional negligence resulting in death and injuries. Before tipping over, his truck hit a passenger car, which then plowed into a bus ahead.

The man had undergone a checkup test for dementia in November 2013 when he renewed his driver's license, but no problems had been found, they said.

Nine elementary school students, including the boy, and the drivers of three vehicles were taken to hospital immediately after the 8:05 a.m. accident in the city just southwest of Tokyo, but the boy was confirmed dead, the fire department said, adding that 11 others sustained minor injuries.

The accident occurred in a residential area close to a downtown shopping district and about 300 meters west of Kamiooka Station.