Five workers fell into the sea and remain missing after box girders along the Jinhai Bridge in Zhuhai, South China's Guangdong province, collapsed during construction at 9:25 am on Sunday, according to a local authority.

The project, in Sanzao township, Jinwan district, is part of the railway being built to link the Zhuhai airport and the city center.

Both the rescue of the missing workers and investigation of the accident are underway, according to the city government.