LONDON -- An 8-year-old girl was killed and more than a dozen people were injured Thursday when an SUV crashed into a private elementary school on a narrow road in southwest London, police said. The crash wasn't believed to be terrorism, and the driver was taken into custody.

The girl died at the scene, Detective Chief Superintendent Clair Kelland said at a briefing near the crash site in London's Wimbledon district.

"Our thoughts are with her family at this incredibly difficult time," said a visibly shaken Kelland, who is the Metropolitan Police force's local commander for southwest London. "The driver of a car, a woman in her 40s, stopped at the scene and has since been arrested for causing death by dangerous driving and remains in police custody."

She confirmed that the crash wasn't being treated as terror-related, but urged people not to speculate as to what happened.

Dr. John Martin, chief paramedic for the London Ambulance Service, said that 16 people were treated at the scene, 10 of whom were hospitalized.

Police were called to The Study Preparatory School, a private all-girls school, at 9:54 a.m., along with paramedics from ground and air ambulances.

Stephen Hammond, Wimbledon's representative in Parliament, said the section of the school where the crash took place caters to younger children between the ages of 4 and 8.

"It is tragically on the last day of term for this young girl to have lost her life," he said.

The crash occurred about a mile away from the All England Lawn Tennis and Croquet Club, which is hosting the world-famous Wimbledon tennis tournament. Unlike the grand slam event, the school is located in a fairly remote area surrounded by local parks, horse trails and golf courses.

Police extended a large cordon around the school and television pictures from overhead showed the SUV, which appeared to be a Land Rover, up against the wall of the building.

Dog walkers and passersby were moved away from the scene as an air ambulance remained on the edge of Wimbledon Common, a large open space, while a number of ambulances were parked nearby.

"Wimbledon is like a little village," resident Julie Atwood said. "For this to happen in Wimbledon is unheard of. It's terrible."