(ABC NEWS) -- Poachers broke into a zoo in Paris overnight and shot and killed a rhinoceros before cutting off one of its horns, zoo officials said today.
The brazen incident is believed to be the first instance of rhino poaching in Europe.
The Thoiry Zoo, located in the suburbs west of Paris, said in a statement that the poachers cut off part of the 4-year-old rhino’s second horn, too, but appeared to have been interrupted by a disturbance in the process or had defective equipment.
Vince, the 4-year-old male that was killed, mostly likely had his horn taken off using a chainsaw, according to the zoo.
The zoo's two other white rhinos, 37-year-old Gracie and 5-year-old Bruno, survived, the zoo said.
World Wildlife Fund (WWF), an international environmental organization that categorizes endangered species and supports conservation efforts, lists white rhinos as "near threatened," rather than endangered and cite poaching as one of the biggest threats to the animal.
“White rhinos are a spectacular conservation success story, but the current poaching crisis could reverse all of our conservation gains," Matthew Lewis, an African species expert writes on WWF's website.
After rebounding from the brink of extinction, there are more than 20,000 white rhinos now alive, mostly in wildlife preserves, according to the WWF.
The French government published a decree in August 2016, prohibiting the transport or sale of ivory taken from an elephant or rhinoceros horn.
No arrests have been made yet in response to the incident, zoo officials said.
The Thoiry Zoo told ABC News that CCTV footage of the incident was handed over to investigators.
ABC News' Paul Pradier contributed to this report.