The Dallas Police Department is investigating another missing animals case at the Dallas Zoo after two tamarin monkeys were reported missing from the zoo on Monday.
A spokesperson for the Dallas PD tells PEOPLE that a preliminary investigation into their disappearance determined that “an intentional cut” was made into a tamarin monkey enclosure at the zoo.
While the investigation remains ongoing, officials believe that the animals were intentionally taken from the enclosure.
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A representative for the Dallas Zoo added in a statement to PEOPLE that emperor tamarin monkeys would likely stay close to home. When the zoo searched near their habitat and across the zoo grounds, they were not able to be located.
Monday’s incident comes after the Texas-based zoo reported a string of missing and injured animal cases in the past weeks.
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Most recently, the Dallas Zoo reported that one of its endangered vultures living in the zoo’s Wilds of Africa habitats was found dead over the weekend and added in a Facebook post on Sunday: “The animal care team is heartbroken over this tremendous loss. Please keep them in your thoughts as they process what happened.”
A 4-year-old clouded leopard named Nova went missing on Jan. 14., prompting the zoo to close for the day.
While she was located near her enclosure later that day, an investigation by Dallas PD on Jan. 16 showed that a cutting tool was used to make an opening in the fencing surrounding Nova’s habitat on the same day of her escape.
The same type of cut was found in the area housing the zoo’s langurs, a small breed of monkey. The cutting of the two enclosures remains under investigation.
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In response to these two incidents, the Dallas Zoo “added additional cameras throughout the Zoo and increased onsite security patrols during the overnight hours,” according to the facility’s post about the vulture’s death.
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“We will continue to implement and expand our safety and security measures to whatever level necessary to keep our animals and staff safe,” the zoo added before concluding the post with a promise to “provide updates as we know more.”