A 26-year-old woman has been shot dead while driving in Milwaukee after a child in the back seat of the car got hold of a gun, police have said.

Milwaukee County Sheriff’s Office said the woman was hit once in the back as she drove on US Highway 175 on Tuesday.

When deputies arrived, the woman had no pulse and was not breathing.

Officers tried to revive her but she was pronounced dead at the scene.

Woman shot dead in car by child in back seat

Emergency services shut down Highway 175 after the shooting

A spokeswoman for the sheriff’s office told the Milwaukee Journal Sentinel that detectives were interviewing witnesses.

The age and gender of the child have not been released.

It is unclear what the relationship was between the woman and the child, what type of weapon was involved or how the child managed to get hold of the gun.

The victim was a mother-of-three who was driving her boyfriend’s car, WISN-TV reported.

The TV station claimed the woman’s boyfriend was a security guard and had left his weapon in the car.

The southbound Highway 175 was shut down for several hours after the shooting.