More than a decade after notorious drug lord Pablo Escobar's death, the hippos that inhabited his personal zoo are now running amok nearby in Colombia, and are presenting a growing problem to locals.

In the early 1980s, Escobar built a zoo on his hacienda, located halfway between the city of Medellin and Bogota, containing smuggled elephants, giraffes and four hippos. He later made it a public zoo. While a grand gesture, now that Escobar is no longer around, the hippos were left unattended to thrive and multiply, causing concern among locals, BBC News reported.

"It's just like this crazy wildlife experiment that we're left with," said San Diego University ecologist Rebecca Lewison. "Gosh! I hope this goes well."

Nobody knows for sure just how many hippos are roaming near the Colombian zoo, but local environmental authority estimates it's between 50 and 60, with most living in the lake at the park.

But some, according to The Wire, have broken free and are causing trouble. Fishermen on the river are scared of the massive beasts, given that they can easily crush their small boats. And farmers are unhappy because the hippos destroy their crops and even "crush small cows."

Hippos are known for being instinctively territorial and supposedly cause more human deaths in Africa than any other animal. But there have been no fatal reports as of yet.

Hippopotamus are native to Africa, where seasonal droughts keep their population numbers in check. But in Colombia, the warm, wet weather is perfect for year-round mating, only exacerbating the situation.

Some suggested solutions are shipping the hippos back to Africa, castrating them or building hippo-proof fences. Although, each solution has its own drawbacks: the Colombian hippos might bring diseases specific to the area back to Africa with them, castration is difficult to execute, and fencing would cost roughly $500,000.

But for Carlos Valderrama, from the charity Webconserva, doing nothing is not an option.

"They are not a tame animal," he told BBC News. "The risk for local populations to just leave them to browse around will be huge."