4 rescued in Chongqing tunnel carbon monoxide leak

Seven people were trapped in a tunnel under construction in Chongqing after a carbon monoxide leak occurred on Tuesday afternoon, Xinhua News Agency reported.

Four of the trapped individuals have been rescued from the Zhongliangshan tunnel, located on the Chongqing section of the Xi'an-Chongqing High-speed Railway, according to local authorities in the report.

Rescue operations are still ongoing, it added.