NANNING - Two workers died and another was injured Wednesday after a subway tunnel collapsed while under construction in South China's Guangxi Zhuang autonomous region, local authorities said Thursday.

The workers were pulled out of the debris and sent to a local hospital by 10:40 pm Wednesday, nearly eight hours after the collapse occurred, according to the municipal publicity department of the provincial capital of Nanning.

Two of the workers died in the hospital, while the surviving worker has minor injuries.

The accident happened around 3 pm Wednesday, when the three were working on a section of subway tunnel located under Minzu Avenue.

The cause of the accident is under investigation.

The accident is the second subway construction-related accident to occur in the last three days. On Monday, five workers were killed and 18 others injured after a platform collapsed in a parking lot being built to support a subway line in Shanghai.