Two people were arrested in Japan after an intruder broke into the enclosure of Punch, a viral macaque at a zoo near Tokyo.

The zoo confirmed that the animals were checked and showed no signs of harm or unusual behavior.

In response, officials announced stronger security measures, including larger restricted viewing areas, intrusion-prevention nets, and constant patrols.

Online footage showed a person in a blue suit and smiley-face mask climbing the fence and entering the zoo, NBC News has reported.

Punch became an internet sensation earlier this year after videos highlighted his social rejection by other monkeys and his attachment to a stuffed toy.