London Zoo visitors had to hide away from the fear gorilla that run from her cage, and was seen only after three full hours, with anesthetic darts fired at her.

Photos taken on social networks shows armed police walking around the area in search of the giant animal. Zoo said that they are “treating the incident happened at the zoo.”

The police were called at around 15:00 pm (local time). One witness told after he was allowed to leave the area of the zoo that “we spent at the zoo, drinking coffee, when they told us that incident and asked us to stay in our place.”

“We tried to understand what was happening and told us that gorilla managed to leave its cage and that we should not go out of the park”, went on to say. “When we left finally saw a very large force of police arrived at the scene.”