The People’s Daily said 15 workers and a project manager were at the site on the bridge spanning the Yellow River in Qinghai province when the rope snapped at around 3 am on Friday.

The bridge on the Sichuan-Qinghai Railway is the world’s largest-span double-track railway continuous steel truss arch bridge, according to the report.

It is also China’s first railway steel truss arch bridge spanning the Yellow River – the country’s second longest – the report said.

Images published on the People’s Daily website showed the partially built bridge, its middle section yet to be completed, with two giant scaffolding towers and several cranes alongside it.

A rescue operation was under way, the report added.

Industrial accidents are fairly common in China due to vague regulation and lax safety standards.

In December last year, 13 people went missing after a cave-in at a construction site for a major railway in the southern Chinese city of Shenzhen. There were no reports of any survivors.