Roughly 70 people were treated for various injuries after being attack by a swarm of carnivorous fish while swimming in Argentina's Parana River, wildlife officials said.
Federico Cornier, the director of emergency services in the city of Rosario, stated that the attacks occurred as swimmers were trying to find some relief during a heat-wave that has seen temperatures hit triple digits in the past week.
The injuries varied from person to person, but some reports indicated that swimmers suffered small lacerations to the loss of entire fingers.
The attack was thought to be the work of palometas, "a type of piranha, big, voracious and with sharp teeth that can really bite," Cornier said.
Swimmers were attacked Christmas Day in Rosario by the fish, which were described as a relative of the piranha, Argentina's state-run Telam news agency reported. The attack happened off the popular beaches of the Parana River near Rosario, about 185 miles north of Buenos Aires
No one was killed, but dozens of people were injured, including a 7-year-old girl who lost one of her fingers in the attack, Telam reported. Most of the injuries reported, however, involved small bite marks on the hands and feet of swimmers as well as lacerations to the lower extremities.
Ricardo Biasetti, sub secretary of Natural Resources for Santa Fe province, said the incident was "isolated and insignificant."
Julian Aguilar, president of a local fisherman's group, said it was unlikely such a thing would happen again.
"This is not normal," Cornier said on television. "It's normal for there to be an isolated bite or injury, but the magnitude in this case was great ... this is an exceptional event."
In response to the attack local officials closed the beach which kept some out of the water for some time, but given the extreme temperatures swimmers were reported in the water the next day.