Kansas City Zoo officials were working to round up chimpanzees Thursday after several escaped from their enclosures into the zoo grounds.

A zoo official told Fox4KC.com that authorities were unsure how many chimps escaped. The zoo closed at 4 p.m..

Julie Neemeyer, a zoo spokeswoman, told the Kansas City Star that the animals are in a "behind the scenes area" at the zoo, away from public areas.

“As a precaution we have all of our visitors in locked buildings, in safety areas,” she told the newspaper.

There were no immediate reports of any injuries. It's unclear how the animals got loose.

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