A total of 16 people were treated on site and 10 were taken to hospital.

One child seen by the Sky News team on the scene was being carried away with a cut to her leg.

Wimbledon school crash - latest

Sky News' Jacquie Beltrao was at The Study Preparatory School on Camp Road, in Wimbledon, and said: "We have certainly seen one child walk out of here limping, carried by both of her parents supporting her.

"They looked absolutely shell-shocked, and couldn't speak. I just said: 'Are you okay?' And her dad nodded his head.

"The child couldn't speak at all.

"They couldn't tell us what had happened.

"He shook his head again - looked absolutely shocked."

Read more:
Girl, 8, dies after car crashes into primary school

A woman in her 40s has been arrested on suspicion of causing death by dangerous driving and remains in custody.

Beltrao said the small private girls' school is set in a "beautiful location" overlooking the Wimbledon Common and a golf course.

"It is not what you expect to happen round here," she said.

"It's nowhere near a main road, it's right in the middle of Wimbledon Common, just a mile or so away from the tennis."

She described a "massive" response with at least 20 ambulances, an air ambulance and firefighters at the scene.