In their homeland in Africa, they are responsible for more human deaths than almost any other animal, but in Colombia, hippopotami have become loved members of the local community and a tourist attraction.

However, in a town close to the city of Medellin, this legacy of the late drug baron Pablo Escobar, is increasingly posing a problem, and one that experts think may soon turn deadly.

Several months ago, one of the hippos burst into a schoolyard in Doradal with both pupils and parents present.

"The mothers get scared when they see an animal of that size," teacher Dunia Arango told AFP.

This time, the uninvited guest chomped at some fruit trees before moving off into the adjacent fields.

But a bloat of hippos has set up a home in a lake just 20 meters (yards) from the school.

"There are about 35 children playing that could approach them and provoke a tragedy," said David Echeverri, an official from the local environmental authority.

"While they may look very calm, at any moment, given their highly unpredictable behavior, they can attack, as has happened before," he added.

John Aristides, 33, remembers very well that afternoon in October 2021 when he was fishing on the banks of a creek when a hippopotamus "lunged at me and hit me on the head with its lips."

He slipped trying to get away and was bitten on the arm.

"It grabbed me and threw me two meters," he added. "It didn't tear off my arm because they have very wide teeth."

But Aristides still spent a month in the hospital recovering.

That is the closest Colombia has come to a fatal encounter but "if we don't do anything, then we expect to have thousands of hippopotami wandering around" in the future, said Echeverri, who two weeks ago buried a hippo that had been hit by a driver.