Seven people were killed and several others were believed to be missing after a ferry sank in Indonesia on Saturday, an official said.

The ferry sank 15 miles (24 kilometres) from Kolaka in Southeast Sulawesi province, port chief Zainuddin said, adding that 93 people had been rescued.

"We have found 61 adults, 13 children and 19 crew members who are still alive," Zainuddin said.

 He said a nine-month old baby boy was among the dead.

 "The rescue team is still searching for several more people. We suspect some people are still missing as the passenger list of the ferry is inaccurate," he said.

Zainuddin said the ferry came from a port in South Sulawesi province and sank as it approached Kolaka, but he did not elaborate on the cause of the accident.

Sea accidents are common in the archipelago and safety standards are often overlooked. (AFP)