More than 100,000 people evacuated their homes on Saturday in South America due to severe flooding after heavy summer rains brought on by the El Nino phenomenon, authorities said. The bordering areas of Paraguay, Uruguay, Brazil and Argentina were the worst hit, reported Reuters.

The Paraguayan government declared a state of emergency in the capital Asunción and seven regions of the country. Several people were killed by falling trees, local media reported, but no definite number was available. At least four people died in Argentina and Uruguay, according to local media reports.

This year’s El Nino, which is linked to global climate fluctuations, is the worst in more than 15 years, according to the United Nation’s World Meteorological Organisation. “Severe droughts and devastating flooding being experienced throughout the tropics and subtropical zones bear the hallmarks of this El Nino,” said WMO chief Michel Jarraud.

Hundreds of people fled their homes in northern England too on Saturday due to flooding, as the Met Office issued two highest-level red weather warnings.