271 people are reported to have been on board the ferry, which was reportedly en route from the city of Surabaya to Makassar in the south-western part of the island of Sulawesi.
Maritime accidents are common in Indonesia, an archipelago of more than 17,000 islands, partly due to poor safety practices and unpredictable weather.
In July, a ferry with more than 70 people on board sank just south of Sulawesi. At least four people were found dead, but several are still missing after that accident.
