At least 10 vessels were searching Thursday for three fishermen missing after their boat capsized off the east China coast late Wednesday night.

A border police officer in Zhoushan city, east China's Zhejiang Province, said nine fishermen, all from Zhejiang, were aboard the boat, which capsized off Zhoushan port at 10 p.m. Wednesday.

He said six people were rescued overnight and were in stable conditions.

The local maritime authority said no extreme weather was reported when the boat capsized, and they were investigating the cause of the accident.