Hundreds of migrant workers from distant corners of China pour daily into the Urumqi South railway station, their first waypoint on a journey carrying them to lucrative work in other parts of the far western Xinjiang region.

Like the columns of police toting rifles and metal riot spears that weave between migrants resting on their luggage, the workers are a fixture at the station, which last week was targeted by a bomb and knife attack the government has blamed on religious extremists.

"We come this far because the wages are good," Shi Hongjiang, 26, from the southwestern metropolis of Chongqing, said outside the station. "Also, the Uighur population is small. There aren't enough of them to do the work."