A man had a toe amputated, a 7-year-old girl lost part of a finger and dozens more were injured after a shoal of biting fish attacked bathers in on a popular river beach in Argentina.

The attack occurred Christmas Day in Rosairo Province, where approximately 9,000 people gathered on the beaches of Rambla Catalunya on the river Parana, about 185 miles (300 km) northeast of Buenos Aires.

More than 70 people were injured by the biting fish, a relative of the piranha known as "palometas," according to a Reuters report.

Officials have suggested the unusually high temperatures in the area may have been linked to the attack, according to RT news, which reported that the fish become more active at higher temperatures.

Biting fish such as piranha and palometas are attuned to pick up even the faintest trace of blood in the water.

"When one of them bites someone it is very probable that the others will move in to attack," a spokesperson from the Ichthyology Laboratory of the National Institute of Liminology told RT.

In a television interview, Federico Cornier, director of the local Emergency Medical Services (SIES), said that the attack seemingly came out of nowhere

"Suddenly people started appearing with bites on their hands and feet. It was sudden," he said.

The most serious injuries were to a 7-year-old girl who had part of a finger amputated on her left hand and to a man who lost a toe in the attack, according to RT. Argentinian newspaper La Capital said that 30 percent of the injuries were to "youths" and that seven children were injured.

"This is not normal," Cornier said on television, according to Reuters. "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."