A teenaged joy-rider ploughed into a group of schoolchildren, killing one of them and injuring 17 others in Nkomene, Nelspruit, on Friday, said Mpumalanga police.

"The children were walking on the side of the road, when a boy driving his uncle's car came speeding down the right-hand lane. He then lost control of the car and hit all 18 pupils," said Inspector Andries Skwambhane. "The car then somersaulted a number of times."

The 16-year-old joy-rider, who was not injured in the incident, was arrested at the scene and in custody, said Skwambhane. He did not attend the same school as his victims.

Skwambhane said the group of Sibambhisene Higher Primary School pupils ? all aged 14 and 15, and most of them girls ? had been walking home from school when they were struck.

All of the injured were taken to Themba hospital. A 15-year-old boy later died of his injuries. Eight others were in critical conditions. The conditions of the rest were serious.

"We are still trying to find the owner of the car, to see if permission was granted to the boy to drive the vehicle. Its a serious offence if he did," said Skwambhane.

"This was a terrible incident and it cost a young person's life," he said.