Police fired tear gas to disperse people gathered around the plane, which, according to the Central Bank of Bolivia, was transporting banknotes of unknown value to the capital.
Authorities later allegedly set fire to piles of banknotes at the scene of the accident.
The incident occurred when a Hercules C-130 military transport aircraft was about to land at an airport in El Alto, near the capital, La Paz.
For unknown reasons, the plane skidded off the runway onto a road, where it collided with several vehicles and ended up in a nearby field.
A spokesman for the emergency services says at least 20 people have died.
