CHENGDU, April 22 (Xinhua) -- Two school heads at a southwest China primary school have been suspended from their posts after a classroom collapsed injuring seven pupils and a teacher, sources with the local education authority said Sunday.

The accident occurred at around 9:30 a.m. on Friday when a decaying wooden girder broke, causing the collapse of the brick building at Zhongjisi Village in Suining City, Sichuan Province, burying the eight people, said Xia Xiantong, director of the local education bureau.

Xia said the accident happened during a break when only a teacher and seven children, all about six years old, were inside. They suffered minor injuries, and were being treated in hospital.

An investigation has been started into the actions and responsibilities of the headmaster and a deputy headmaster who was in charge of school safety, Xia said.

The education bureau has required all schools in the area to inspect all classrooms for safety risks, Xia said.

The rural primary school had eight classrooms and about 100 students. The classroom was built in 1970 and had undergone several renovations.