Sixty-six people are feared to have drowned after an overloaded wooden boat carrying 97 migrants from Indonesia sank off Malaysia's western coast, Malaysian officials said.

The passengers included women and children and the boat was not fit for a sea voyage,  Muhammad Zuri, an official with the Malaysian Maritime Enforcement Agency, said on Wednesday.

"This was an illegal boat and all the passengers were Indonesian," Zuri told Reuters.

Zuri had earlier said that 61 people were missing, but later clarified that only 31 passengers had been rescued.

The agency had sent one boat to the area to search for survivors and was sending two more, the spokesman said.

Malaysia's New Straits Times said the boat sank around midnight on Tuesday about 3km from the coastal town of Banting on the Strait of Malacca.

(Aljazeera)