An attack by a school of carnivorous fish has injured at least 10 people bathing in an Argentine river over the past two days.

The attack took place in the Parana River in Rosario some 300 kilometres northeast of Buenos Aires.

Seventy people who were cooling off from high temperatures were also injured in late December by the same piranha-like fish.

They included seven children who lost parts of their fingers or toes.

The latest attack by the “palometas” was confirmed on Saturday.

They’ve been described by the local director of lifeguards as “a type of piranha, big, voracious and with sharp teeth that can really bite.”

Media reports said the injured included a boy who suffered a foot wound while floating in the river.

Experts say unusually high temperatures during the Austral summer and lower numbers of species such as caiman that preyed on the fish could be causing the attacks.