The KM Sinar Bangun boat sank on June 18 as it sailed from Samosir, a volcanic island in the middle of Lake Toba to Parapat town.
Indonesian authorities confirmed that three died in the accident while 193 are missing, including children. Only 18 were rescued.
The boat is still missing four days after the accident, despite a large scale search with the involvement of 400 personnel.
It was not immediately clear whether any foreigners were among the passengers. Most of the passengers are holidaymakers enjoying the country's 12-day-long Eid al-Fitr holiday.
The accident is said to be one of the worst waterway tragedies in Indonesia, where ferry accidents are common as the country is an archipelago of more than 17,000 islands.
Indonesian police have arrested the captain of the passenger boat, who was among 18 survivors in the accident.
Indonesian Ministry of Transportation has decided to halt the operation of all tourism boats in Lake Toba in seven days to serve the search for victims.
During the suspension, all boats will undergo safety checks. Only those meeting safety standards of Indonesia can resume operation after the restriction time to avoid similar accidents.
Lake Toba is the largest volcanic lake in the world and a popular spot for local and international tourists.-VNA
