Thirteen people including a child are missing after a ship and a tugboat collided in waters 18 kilometres (11 miles) north of Indonesia's capital, an official said on Thursday.
All 26 people on the Rimba 3, which was carrying cement from Jakarta to North Sumatra province, went overboard after it sank early Thursday, Tanjung Priok port official Bobby Mamahit told AFP.
Rescuers plucked eleven crew members and two of their wives from the water but a navy and maritime police search team had still not found 12 crew members and one child, Mamahit said.
The tugboat, which was heading from South Sumatra to Jakarta, did not sink.
"We suspect there was a navigation failure. The weather was normal when the accident happened," he said.
An archipelago of more than 17,000 islands, Indonesia is heavily reliant on sea links but safety standards are poorly monitored.
Up to 350 people died after the Indonesian ferry Teratai Prima sank in the Makassar Strait off Sulawesi island in January.