More than 70 people were injured after a school of fish attacked bathers in the Parana River on Christmas Day.
Thousands of bathers are reported to have taken to the water at Rosario — a city located around 185 miles north of Buenos Aires — due to the extreme temperatures, which topped 38°C.
But around mid-morning, people began to shout that they had been bitten.
Medical officials described the attack as "very aggressive", with some of those bitten having lumps of flesh torn from them. Some of the children who were injured are reported to have lost entire digits.
The fish responsible was described by bathers as 'palometa': a carnivorous fish of the piranha family — probably Pygocentrus palometa.
Officials said the unusually warm weather may have been responsible for the fish congregating at the water surface prior to the incident.
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