DALLAS (AP) — The Dallas Zoo shut down Friday after a clouded leopard was discovered missing, setting off a daylong search and criminal investigation after police say they found evidence that the fence of the small cat’s habitat had been “intentionally” cut.

The search for the cat named Nova, who zoo officials said weighs about 20-25 pounds (9-11 kilograms) and does not pose a threat to humans, closed Texas’ largest zoo to visitors as the animal remained missing since the morning discovery.

As the search dragged on, officials appeared more open to the possibility that Nova may no longer be on the grounds of the 100-acre (40-hectare) zoo.

Clouded leopards are considered a vulnerable species and one of “conservation concern,” said Harrison Edell, executive vice president of animal care and conservation at the Dallas Zoo.

Police and zoo officials said they have reviewed surveillance footage but would not say what it showed or whether there were potential suspects.

“It is our belief that this was an intentional act,” Dallas Police Sgt. Warren Mitchell said. “We have started a criminal investigation.”

Mitchell said Dallas police at first dispatched SWAT officers to the zoo, not understanding the size of a clouded leopard. Police drones have helped search the zoo grounds, including trees, which Edell said clouded leopards like to climb.

The zoo tweeted that the missing cat, named Nova, was a “serious situation,” but officials said the animal posed no danger.

“We’re hoping it’s still here somewhere,” Mitchell said.

Another clouded leopard at the zoo, Nova’s sister, was still in its habitat. Edell said they believe Nova is likely to stay close to home despite leaving her enclosure.

Animals have escaped enclosures from the Dallas Zoo before. Most notably was in 2004, when a 340-pound (154-kilogram) gorilla named Jabari jumped over a wall and went on a 40-minute rampage that injured three people before police shot and killed the animal.