Indonesia's National Search and Rescue Agency said the sinking of the KMP Tunu Pratama Jaya ferry occurred nearly half an hour after the ferry left Ketapang port in East Java on the night of July 2.
The ferry sank at around 11:30 p.m. on July 2 in the Bali Strait while carrying 53 passengers, 12 crew members and 22 vehicles, including 14 trucks.
Two bodies have been found and 20 people have been rescued, many of the victims were unconscious after drifting in the rough seas for hours.
There are 9 boats, including 2 towing boats and 2 inflatable boats, participating in the search for missing people. The weather in the sea area where the ferry was in distress had waves up to 2m high.
Maritime accidents often occur in Indonesia, an island nation of about 17,000 islands in Southeast Asia, where ferries are often used as a means of transportation and safety regulations are violated.
In March this year, a boat carrying 16 people capsized in rough waters off Bali, killing one person and injuring at least one.
In 2018, more than 150 people died while a ferry sank in one of the world's deepest lakes on Sumatra Island.