An overloaded ferry sank in bad weather off Indonesia's Riau islands on Sunday, killing 29 people, while 245 passengers survived the accident, according to officials.
The Dumai Express 10 was sailing from Batam near Singapore to Dumai island in Riau when it ran into huge waves, police chief Puji Hartanto said.
Health Ministry official Rustam Pakaya told Reuters that 17 people were still missing. A total of 291 people were on board, including 13 crew.
Survivors have been spotted floating at sea but bad weather and six-metre-high waves are hampering search and rescue efforts.
Earlier, a Transport Ministry official told a news conference in Jakarta that the ferry, which had the capacity to carry 273 people, had 213 passengers on its manifest.
"The disparity between the manifest and reality is large, it's such a classic case of breaking the regulations, said Mr Sunaryo, director general of sea transportation.
Another ferry, the Dumai Express 15 with 278 people on board, ran aground after it was hit by large waves, according to Riau police.
The ferry was travelling between Batam and Moro island and all on board survived.
Indonesia relies heavily on ferry services to connect the many islands in the sprawling archipelago.
But accidents are common, largely due to years of under-investment in infrastructure and a tendency to overload ferries.