Two people have been detained by police over a three-year-old girl's death on Wednesday in a school bus in South China's Guangdong Province, local authorities said on Friday.

Zhong Miaolin, a kindergarten pupil, was left in a school bus in Yingde City on Wednesday morning and was found dead at 3:40 p.m., according to the municipal government.

Zhong suffocated to death after being left in the vehicle for too long. The temperature in the bus was very high given the hot weather, said police.

The driver of the bus and a teacher accompanying the children in the vehicle are under criminal detention for their negligence of duty. They did not notice the girl was left in the bus after it arrived at school, according to the police.

The kindergarten has been suspended from operation. The municipal government has began an overhaul of all the school buses in the city over safety concerns.