HEFEI - A ferry sank in East China's Anhui province early Thursday morning, leaving a dozen people missing, local authorities said.

The accident occurred at about 1:40 am when a ferry carrying 21 people sank in the Ma'anshan section of the Yangtze River, the Anhui Provincial Emergency Management Office announced in a statement.

Nine of them have been rescued, and they are in stable condition, the statement said.

It said the boat, which was not overloaded, was travelling from Ma'anshan city to Hexian county when the accident happened.

At least nine boats are searching for the missing people.

Investigation into the cause of the accident is under way.