Chester Zoo, Britain‘s most popular wildlife attraction, was evacuated on Sunday, 5, after 30 chimpanzees escaped from their enclosure. At the moment of the runaway about 5,000 visitors were asked to leave the zoo site as a security measure. The animals made their escape at lunchtime and found their way into a keeper area where their food is normally prepared.

There were no injuries to members of the public or staff and the zoo said the decision to evacuate was taken as a precautionary measure. It apologized for the incident and an investigation was underway into how the animals escaped. The zoo’s blacksmith was visiting the area on Monday, 6, to examine the door latches.

Refunds were offered to visitors after the site evacuation and the zoo thanked everyone for the cooperation and patience. The zoo also informed in an official communication that anyone who had not yet claimed their money back should contact the ticket office or can choose to make a free visit to the zoo.