NANNING - Two of three workers trapped in a collapsed tunnel of a metro line under construction in the southern Chinese city of Nanning have been rescued.

The accident happened at around 3 pm in the tunnel under Minzu Avenue in the capital city of Guangxi Zhuang Autonomous Region. One worker remained trapped

Rescuers said the three workers were working in the tunnel section, where there were two sewage pipelines. The cause of the accident is not immediately known.

The rescue work led by mayor Zhou Hongbo is continuing.