Bolivian officials say at least 19 people are known dead, and another 40 are missing after a bridge collapsed into a rain-swollen river earlier this week.

Authorities say most of the victims were on a passenger bus carrying about 45 people. At least three other vehicles were swept into the river, including a military vehicle used in army anti-drug operations. At least two soldiers were killed.

Officials say six people were rescued after the incident Tuesday in the Chapare river near the town of Villa Tunari, nearly 650 kilometers southeast of La Paz.

A search continues for possible survivors and the bodies of victims believed to have been swept away in the raging river after the collapse of the 350-meter-long bridge.

Heavy rains are blamed for the collapse, and for other damage in the area. The Bolivian government has declared a state of emergency in the region.

Some information for this report provided by AP, AFP and Reuters.