Bolivian President Evo Morales has declared a national disaster as his government tries to cope with the aftermath of widespread flooding.
Parts of Beni's main city Trinidad are under water
Floods caused by rain have left more than 60 dead in the eastern lowlands.
Mr Morales on Monday toured the worst-hit province, Beni, where thousands of people have had to leave their homes amid rising floodwaters.
It is the second year in a row that Bolivia has seen such floods, which officials blame on climate change.
The floods have left more than 40,000 people homeless, officials say.
Rivers have broken their banks and floodwaters are threatening to breach a raised road surrounding the provincial capital of Trinidad, home to some 90,000 people.
The government has been distributing food and tents in Trinidad, while rescue teams backed by helicopters from Brazil have been stepping up operations, a presidential spokesman said.
Mr Morales' declaration authorises the government to release funds to help tackle the crisis.
The president had been under pressure to act from opposition governors in the eastern states, who had accused him of reacting too slowly, the Associated Press news agency reported.
Since November, several parts of Bolivia have suffered floods.
The United Nations says the flooding is expected to get worse as more rain is forecast.