The director of Cincinnati Zoo has defended the decision to shoot dead a gorilla after a four-year-old climbed into his enclosure. The 17-year-old silverback, named Harambe, was killed on 30 May.

In the incident, the child was dragged around the enclosure by his ankles by the gorilla before zookeepers took the decision to shoot the animal. The boy's head was reportedly banging against the concrete floor during his ordeal.

Commenting on the incident, Thane Maynard, director of the zoo, said: "Looking back, we would make the same decision. I know that after it is over, and the child is safe, it's easy like a Monday morning quarterback to look at it and say, 'wow, wow, wow, don't we need to do this differently.'

"The people that say that, don't understand primate biology and silverback gorillas and the danger the child was in, and were not there at an important time to make important decisions. We stand by our decision, we'd make the same call today."

Maynard added that they did not tranquillise the animal over fears it would enrage him and put the child's life in even more danger.

However, the decision to kill the gorilla has led to condemnation on the internet. More than 290,000 people have signed a petition on to protest against the shooting. Some animal rights campaigners have claimed that Harambe was actually protecting the child.

Despite the reaction, Maynard insists that the zoo followed the right course of action, adding: "Naturally, we did not take the shooting of Harambe lightly, but that child's life was in danger. And people who question that, or are Monday morning quarterbacks, or second guessers, don't understand that you can't take a risk with a silverback gorilla. They're very big, three times bigger than a man, six times stronger than that. This is a dangerous animal."

Cincinatti Zoo is planning to review its barrier policy to see if the incident could be prevented from happening again in the future.