A 4-week-old baby boy has died after being involved in a “drunk” car accident on the Japanese island of Okinawa.

Authorities in Okinawa said the car involved in the accident, which occurred Friday evening in the city of Okinawa Prefecture, was being driven by a mother who had previously been in a traffic accident.

An ambulance and a fire engine were sent to the scene to help the infant, who had been rushed to a hospital in Yokohama.

His death was initially reported as a homicide.

According to police, the infant was found unconscious and unresponsive in a car seat.

An autopsy later determined the cause of death to be “multiple blunt force trauma.”

Authorities said the mother is still being questioned.

The car’s license plate number was not immediately available.

The baby’s mother, who was not named, is being held on suspicion of vehicular manslaughter, according to police.

The baby’s father is also being questioned by police.

The infant’s mother was arrested on suspicion that she was drunk at the time of the accident and also for driving while impaired, police said.

Authorities said they have not yet identified the mother or the baby.