A teenage boy crashed into his mother outside a driver examination centre in Brisbane this afternoon, partially severing her leg.

The 17-year-old drove the four-wheel-drive Toyota Hilux into a group of seats outside the Zillmere Queensland Transport Centre, Pineapple Street, about 12.30pm after completing a driving test.

Police believe the boy's 46-year-old mother, who was waiting for her son near the seats, was pinned to a wall by the car.

According to emergency services, the woman was taken to the Royal Brisbane and Women's Hospital with a partially severed leg but in a stable condition.

The boy was treated for shock, as was an elderly woman who witnessed the incident.

Police are still investigating the cause of the crash.

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