US mother fatally shot by two-year-old son

A two-year-old boy fatally shot his mother from the backseat of the car as she drove along a Milwaukee highway, relatives say.

Patrice Price is seen in an undated photo provided by her father, Andre Price. She was fatally shot in the back. Source: AAP

Relatives say a woman was fatally shot in the back by her two-year-old son as she drove in Milwaukee.

Antonio Price says investigators told him his sister Patrice was driving with her two sons, ages one and two, riding in the backseat on Tuesday when she was shot.

Price says investigators told him the older boy fired the gun.

He says his mother was in the passenger seat and was not hit.

Milwaukee County sheriff's officials haven't identified the victim, but say a 26-year-old woman was shot once in the back while driving on Highway 175.

Price says his sister was a great mother and always gave him good advice.

The woman's father, Andre Price, says his daughter was driving her boyfriend's car when she was shot.