This gruesome video shows a man with the tip of his big toe missing, revealing a bloodied open wound, following a red-bellied piranha attack in a river.

The attack took place in the Parana River on its course through the small city of Coronda in the east-central Argentinian province of Santa Fe.

It was not reported when the attack happened. However, it was reported by local media.

In the latest incident, a father and son, both unnamed, went for a dip in the river and were attacked by a shoal of piranhas.

As can be seen in these gory photographs, the man had the tip bitten off his big toe and his son had a chunk torn from the heel of his foot, both leaving gaping wounds.

According to witnesses, the attack took place as soon as the pair entered the water, and they had to run back out immediately. They received first aid from lifeguards and were then taken to a medical centre.

According to local media, such attacks occur during hot weather. They are more common during the Argentinian summer, when the fish reproduce and come close to the coast when water levels are low.

The same location saw a spate of red-bellied piranha attacks over two consecutive days around a month ago, resulting in at least 20 injured.

The red-bellied piranha (Pygocentrus nattereri) is a widespread freshwater fish that is native to South America. It can reach up to 20 inches in length, but rarely surpasses 14 inches.

It mainly feeds on plants and insects, but it is a known carnivore and sometimes eats animals as large as egrets or capybara when in hundreds-strong packs.