Locals in Paraguay are voicing concern on the danger brought about by piranhas, having killed four victims and injured 20 others in different attacks this year, FOX News reported.

A piranha attack was recorded last Jan. 2, victimizing a 22-year-old man who disappeared during a family gathering as he was dragged underwater off the Paraguay River, located at Itá Enramada, south of the capital Asuncion.

The incident was reported to the police by his family.

An hour later, the man, suffering from serious piranha bite marks, was located.

A soldier sails toward a pontoon at the Parana River, in Ciudad del Este Paraguay Oct. 12, 2021. (REUTERS/Cesar Olmedo)

Another male victim, 29, was also killed after a piranha attack in the same river, from a location in Puerto Rosario town. He went swimming, then drowned due to the fish attack. A report said the victim suffered from injuries on the face.

The third death from the fish attack involved a man who was retrieved by the Naval Prefecture and the Public Ministry on Tuesday. The victim was seen floating in the Paraguay River, with piranha bites on his face and feet. Later, he was determined by a forensic doctor to have died of asphyxia by submersion.

Apart from the three, two more piranha attack deaths were recorded in Tebicuary River branch in Villa Florida. An Argentine newspaper reported that the victims’ bodies also had bite marks.

More reports of injuries among swimmers and bathers were raised in other beach areas – with piranha still the culprit.

The ferocious fish are notably aggressive from October to March as these months are time for them to breed. They do not commonly attack humans unless it’s breeding season or in times of drought. A report, however, said that attacks from these fish do not usually lead to death.