The train "used for seismic equipment testing" collided with construction workers at Kunming's Luoyang Town station in the early morning, killing 11 and injuring two, the Kunming Railway Bureau said in a statement.

The train was "passing normally through a curve inside Kunming Luoyang Town Station when a collision happened with construction workers who had entered the track area", it said.

The cause of the crash was under investigation, authorities added.

Transportation had returned to normal by midday Thursday, with those injured receiving treatment, they said.

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