A man in his 30s is in custody and assisting police over the alleged abduction of a girl walking to school on the southern outskirts of Perth. The girl was seen being picked up in an unknown vehicle during the morning school run. The nine-year-old was found a short while later at a shopping centre in Port Kennedy, a few kilometres away. A staff member from a local supermarket says the schoolgirl had walked into the store's back entrance visibly upset and asked for help. Police say a parent saw the child getting into the vehicle felt something was wrong and immediately reported it to the school.