(Newser) – This was a Christmas Day feeding frenzy that didn't involve shrimp cocktail and cookies. Piranhas attacked 70 people in Argentina yesterday, including seven children who lost parts of their fingers or toes. A heat wave has driven temperatures north of 100 degrees, leading hordes of people to attempt to cool off in the Parana River—home to plenty of the carnivorous fish, which officials believe had moved nearer to the surface due to the weather, too, reports the AFP.

An official blamed the attack on palometas, "a type of piranha, big, voracious and with sharp teeth that can really bite," reports the AP. Many people had bits of flesh "literally torn off" in the "very aggressive attack," which happened in Rosario, about 200 miles north of Buenos Aires. Crazy enough, a paramedic said that the heat drove some people back into the water within 30 minutes of the attack. (Read more piranhas stories.)

