Rescuers work at a tunnel blast site in Dafang County, southwest China's Guizhou Province, May 2, 2017. (Xinhua/Han Xianpu)
A blast ripped through a railway tunnel under construction in Guizhou Province Tuesday, leaving 12 people injured and 12 others trapped, local authorities said.
The accident happened around 2:50 p.m. in the Liulong Township of Dafang County, a spokesman with the county government said.
A gas explosion is suspected as the Qishanyan Tunnel is designed to pass through a coal seam, the spokesman said.
The injured have been rushed to hospital.
Rescue work has been suspended because of high carbon monoxide density at the site.
The cause of the accident is being investigated.