Officials in Caceres warn that thousands of hungry piranhas have been attacking tourists at a popular Paraguay River beach...for about 2 weeks.
At least 15 swimmers have been attacked...and one lost part of a toe...at Daveron Beach.
It's the first time ever the ferocious flesh eating fish have been seen at the beach.
A fireman told Globo TV: 'People have got to be very careful. If they're bitten, they've got to get out of the water rapidly and not allow the blood to spread.'