A school of carnivorous fish attacked hundreds of Argentines cooling off in a river near the city of Rosario, sending at least 70 to local clinics and emergency rooms for treatment.
The attack by palometas, a type of piranha, occurred as city dwellers attempted to escape the 100-degree heat of Christmas Day in the Southern Hemisphere's summer season.
"There were some people that the fish literally had torn bits of flesh from," a medical official at the scene, Gustavo Centurion, was quoted as saying by the Latin Times newspaper.