JOHANNESBURG – A minibus carrying young students collided with a truck and burst into flames in South Africa on Friday, killing about 20 children.The victims were between 5 and 10 years old, said Russel Meiring, a spokesman for paramedic company ER24. He said several children survived after being pulled from the wreckage near Bronkhorstspruit, east of the capital, Pretoria.Images posted by ER24 on Twitter show the crumpled, smoking minibus on its side next to the truck. Authorities were investigating the cause of the crash. "We are trying to find out exactly what happened," Meiring said.Some students who were trapped in the minibus were burned beyond recognition, the News24 website reported. It quoted Johan Pieterse, spokesman for the EMS paramedic company.Transport Minister Joe Maswanganyi expressed condolences to the families of the dead. In an interview with the eNCA news outlet, he said many accidents occur because of reckless driving and that increasing the police presence on the roads would have limited results."If human behavior doesn't change, there isn't much that police can do," he said.A total of 235 people died in accidents on South Africa's roads during the recent Easter period, a 51 percent increase over the same period last year, according to the country's Road Traffic Management Corporation.