WATCH: 'Stressed' 7-Ft Gorilla Sparks Panic After Banging Window, Escaping Glass Enclosure

A few days ago, a resident gorilla in a London zoo named Kumbuka managed to escape his enclosure. United Press International said in a report that the 18-year-old endangered western lowland silverback gorilla was filmed smashing the glass window of his enclosure moments before he escaped.

Eyewitnesses Hannah O'Donoghue-Hobbs and Charlotte Neild told BBC that the gorilla appeared to be "really angry" and was "banging on the cage." His escape resulted in a brief panic among the visitors who were in the area. A lockdown was immediately called as the visitors were ushered in a safe place.

Meanwhile, zoo officials said Kumbuka did not break the glass wall, but rather escaped through an open door into a secure area accessible only by zookeepers and not by the public. Many concerned citizens feared that Kumbuka's fate might suffer the same fate of Harambe, a Cincinnati zoo endangered gorilla who was shot dead after a boy fell from its enclosure.

READ: #RIPHarambe: Who Was Harambe? Facts About the Critically Endangered Animal

Kumbuka is now back in his enclosure after the officials were able to tranquilize him. Terry Maple, an expert in animal's psychological responses to captivity and the former head of Zoo Atlanta told National Geographic that gorillas, who prefer to avoid people, are very powerful and they must be treated with respect.

Appearing on "Good Morning Britain," Sir David Attenborough, a naturalist and broadcaster, said he felt sympathy and sorrow for the escaped gorilla and urged the people to be sensitive towards the animal. He added that the gorilla might have felt "fed up" from people watching him for ten hours outside the glass enclosure.

"Sometimes visitors to zoos are not respectful and they start shrieking or waving their arms in order to get the poor gorilla to do something," Attenborough said. "You might think, oh they're just animals. They are not just animals. They are related to us. They value their privacy. Just imagine what it's like to be there. [...] That finally the alpha male, the big gorilla, got fed up with it, is hardly surprising."