The collapse occurred on Monday in Fenghuang County in Hunan province, the official Xinhua News Agency said.

Dozens of people are reported to be missing. The cause of the collapse is under investigation.

The 320-metre bridge was being built to span the Jiantuo River, Xinhua said. Fenghuang is a hilly area popular with Chinese tourists.

Rescuers are searching for survivors. Most of the people who were working on the bridge are thought to be local farmers who had been recruited for the project.

The bridge was designed to be a tourist attraction, Xinhua said. It was scheduled to open at the end of August.