Officials say flooding from heavy rains has killed 12 people in three South American nations and forced more than 20,000 to flee their homes.

Most of the dead are in southern Brazil — including eight in Rio Grande do Sul, according to the state's Civil Defense Department.

Sustained stormy weather has saturated the region and caused the river between Uruguay and Argentina to overflow its banks.

Government agencies report that 10,000 people have been evacuated in Brazil, along with 8,000 in northeastern Argentina and 4,000 in Uruguay.