A wooden boat was carrying 25 boarding school male students across the Bengawan Solo river on Java when it capsized due to suspected overloading.
Seven teenagers were feared dead Saturday, a day after they went missing when their boat capsized on a river in Indonesia, officials said.
None have been found despite a major rescue operation.
The wooden boat was carrying 25 Islamic boarding school male students across the Bengawan Solo river on Java when it capsized early Friday.
Officials said they suspected overloading caused the boat to tilt.
"They were about to reach land, about seven metres away or so, but the kids, probably from over excitement, came to the front of the boat, making the boat unbalance," Suprapto, a local disaster management official, told AFP.
The missing passengers were aged between 12 and 19. Eighteen other passengers survived, Suprapto, who like many Indonesians goes by one name, added.
According to local media, three rescue teams were deployed to search the river using inflatable boats soon after the accident but none of the missing has been found so far.
Rescuers said rain, muddy water and strong currents were hampering the search.
Indonesia has a poor water transport safety record and regularly suffers fatal boat accidents.
Last month, an explosion on a speedboat on the resort island of Bali left two foreigners dead and 18 other tourists injured.
This is not the first incident dues to using traditional boats at the Bengawan Solo River. In May 2011, a boat carrying 40 oassengers sank while another carrying 10 passengers and six motorcycles capsized.