An eight-year-old girl has died and several other children and adults are injured after a car hit a building at a south London primary school.

Local media reported the children had been holding an end-of-term tea party with parents and teachers in the garden of Study Prep School in Wimbledon, about 1.6 kilometres from the site of the ongoing tennis tournament.

“The driver of a car, a woman aged in her 40s, stopped at the scene and has since been arrested for causing death by dangerous driving and remains in police custody,” senior police officer Clair Kelland said outside the school on Thursday (British time), at times fighting back tears.

Asked how the vehicle, a Land Rover, could have crashed into the school, Ms Kelland said she would not speculate.

The capital’s Metropolitan Police said the incident was not being treated as “terror related”.

A total of 16 people, including several children, were treated at the scene and 10 were taken to hospital, emergency services said.

“The school community is profoundly affected by this tragedy and, at the moment, we’re really not in a position to make any further comment about it,” John Tucker, chair of the school’s board of governors said.

A spokesman for British Prime Minister Rishi Sunak said he thanked emergency services for their response.

“The Prime Minister’s deepest condolences are with the family of the girl who has tragically lost her life and his thoughts are with all those injured and involved in the horrific collision in Wimbledon this morning,” the spokesman said.

“This will have been a terrifying experience for all the children, staff and parents.”

Several ambulances, including the air ambulance service and fire officers were involved in the response to the incident.

-AAP