JAKARTA - At least 23 people died and 6 others remained missing after a wooden ship sank in a river in East Kalimantan, Indonesia last week, a rescuer said on Monday.

The rescuers have evacuated safely 83 people, said Rima Trisetyaningsih, who is in charge of the East Kalimantan Search and Rescue Office.

"Overload is possibly the cause of the accident in Mahakam river," she told Xinhua by phone.

KM Surya Indah ship capsized in the river located between Melak and Maura Paku at 11 pm local time Thursday, according to the office.

Search and rescue operation continued on Monday, involving those from local search and rescue office, military, police and sailors. ?

Water transport is one of favorite transport mean in the vast archipelago country, but lack of safety has frequently triggered accident.