BEIJING - AT LEAST one person died on Saturday and another 16 are missing after a road collapsed into a subway tunnel under construction in the eastern Chinese city of Hangzhou, state media reported.

More than a dozen vehicles are trapped in a huge crater which was created when the tunnel caved in and has now begun filling up with water from a nearby river, the Xinhua news agency said.

Divers are searching for people still trapped in the vehicles and some 2,000 rescuers are working to pump water out of the tunnel and haul the vehicles from the crater, it said.

Witnesses told the agency 27 people travelling on a bus that fell into the crater managed to escape when the driver opened the door. Nineteen people have been taken to hospital, rescuers said.

Witnesses and rescuers earlier told Xinhua at least 50 people were trapped underground, but the exact number is still unknown. They are believed to be mostly labourers who were working on the tunnel's construction.

Mr Zhu Juzhong, a 56-year-old worker being treated for his injuries at a local hospital, said he was some distance from the site of the collapse.

'Lots of workers immediately rushed to the hoist to be lifted above ground... Some colleagues who moved slowly were buried,' he said.

The tunnel was part of a new subway system being built in Hangzhou. -- AFP