MEXICO CITY (AP) — Mexican environmental authorities have launched a criminal investigation into the death of a crocodile.

The young croc was hung from a tree with a note that read: "We are going to continue killing these disgusting animals unless they are brought under control."

The office for environmental protection said Thursday that the reptile's carcass was found in the Pacific coast resort city of Puerto Vallarta on Tuesday.

It was hung by its tail, and a stick had been stabbed into its head with the hand-written note.

Authorities acknowledge that crocodiles sometimes wander around the tourist zone, but they have set up signs to warn people and are working to improve their emergency response.

Crocs are a protected species in Mexico and killing them is a crime.