Twenty-seven pupils were injured, including four in serious condition, after falling from a two-storey teaching building in south China's Guangxi Zhuang Autonomous Region Thursday, local authorities said.

One pupil is being examined by doctors in hospital after after falling from a two-storey teaching building in south China's Guangxi Zhuang Autonomous Region Thursday. [Xinhua]

The accident occurred at about 4:40 p.m. after the collapse of the porch guardrail on the second floor at Luoman Central Primary School in Liujiang County of Liuzhou City, the county's publicity department said in a statement.

All the injured are being treated at hospitals in Liujiang and Liuzhou, it said.

The guardrail collapsed after being crushed by dozens of students who rushed to the second-floor of the 31-year-old building to return sports equipment after a physical education class, the last class of the day.

A total of 27 students lost control and fell from the second floor, the department said.

The building has been listed as a level 2 dangerous building in a 4-level category, but it can still be used according to regulations, it said. Level 4 is the most dangerous.