Bodies have been washing up on the banks of the Mollepunku River since the incident late Friday near the town of Pampahuasi, 700 kilometers southeast of the Andean nation's capital La Paz, police said.
The passenger bus had been carrying 39 people, and regional police commander Iver Marquez said the truck was carrying two people at the time of the accident, indicating the final death toll may rise.
Firefighters were on the scene recovering bodies and locating any survivors, Marquez said.
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