Large areas of Paraguay, Uruguay, Brazil and Argentina have seen mass evacuations after severe floods, blamed on El Niño. Several governments have declared states of emergency.
Of the estimated 140,000 people evacuated across four countries over the past two days, Paraguay is the hardest hit. At least 100,000 residents - mostly around the capital city of Asuncion - were forced to move to temporary shelters.
Officials said many of those displaced were poor families living in precarious housing along the banks of the River Paraguay. They expect the waters to rise even further, predicting that thousands more people may be affected in the coming days.
Elsewhere in the region, Argentina reported 20,000 people evacuations, with a further 9,000 in Uruguay and around 7,000 in Brazil.
The severe floods left six people dead - four in Paraguay and two in Argentina. Thousands remained without power on Saturday.
All countries deployed their national emergency teams to the affected areas to help those displaced by the flood waters, which were blamed on particularly heavy summer rains.
Emergency funds pledged
In Paraguay, President Horacio Cartes declared a state of emergency, freeing up around 3.2 million euros ($3.5 million) in disaster funds.
"We cannot abandon the thousands of families who each year are affected by flooding," Cartes said in his Christmas message.
Similar measures were introduced in several northern areas of Uruguay.
In northeastern Argentina, a sudden rise in the level of the Uruguay River caused the most serious flooding in 50 years in Entre Rios province. Two years ago, similar floods left scores dead in Argentina.
"We are going to have a few complicated months," said Ricardo Colombi, the governor of the Corrientes region, after flying over the worst affected areas, adding that the consequences for his constituency would be serious.
And in Brazil, President Dilma Rousseff flew by helicopter to survey the damage in southern Rio Grande do Sul state and released 1.5 million euros ($1.7 million) in emergency funds.
El Niño blamed
Forecasters said an unusually strong "El Niño" weather pattern, associated with long periods of warming and in the central and eastern tropical Pacific, sparked the extreme conditions.
Last month, the UN's World Meteorological Organization warned the phenomenon was the worst in more than 15 years, and one of the strongest since 1950.
mm/rg (AFP, AP, Reuters)