JINAN, May 9 (Xinhua) -- Twelve people, including 11 kindergarteners, were killed Tuesday when a school bus crashed and then burst into flames as it traveled through a tunnel in Weihai City, Shandong Province, east China.

Of the 11 children, who were aged between three and six, five were Republic of Korea nationals and six Chinese nationals. They were all students at an international kindergarten in Weihai, local authorities said.

The accident occurred at about 8:59 a.m. inside Taojiakuang tunnel in Huancui District when the bus was on its way to the kindergarten with 13 people onboard, including the children's teacher.

The driver also died and the teacher has sustained serious injuries.

The provincial government has assigned a team to investigate the incident. It will be headed by a vice provincial governor.