At least 23 people were killed and 32 injured when a bus plunged into a river in the Andes mountains in southeastern Peru.

The overnight bus departed from the city of Puerto Maldonado on Thursday and was carrying 56 passengers to the city of Cusco, some of whom were on their way to vote in Peru's presidential election tomorrow.

The bus tumbled into the Mapacho river in a sparsely populated rural area.

A truck was thought to have cut in front of the bus causing it to swerve off the road, police said.

The injured were taken to hospitals in Cusco and a nearby town.

Fatal road crashes are common in Peru, in part because of lax traffic enforcement but also because of the Andean country's challenging mountain terrain.

On 18 January at least 16 people were killed and ten injured when a bus plunged off a mountain road into the Tarma river in the central region of Junin.

Road crashes killed 2,798 people in 2014, according to the latest figures from the interior ministry.