HANGZHOU - Five workers died and another one was injured in a construction accident early Wednesday morning in East China's Zhejiang province, local authorities said.

The accident happened 19 minutes after midnight in the Beilun District of Ningbo city when the employees were carrying out tunnelling work for water supply. The work was being done by Ningbo Industrial Water Supply Co Ltd, according to the district's publicity department.

The injured worker is in stable condition, it said.

The under-construction water supply route, measuring about 6.93 km long, is designed to have a daily water supply capacity of 150,000 tons upon completion.

An investigation into the cause of the accident is under way.