Dublin Zoo is investigating after a young boy was photographed inside its rhino enclosure at the weekend.

The images appeared online, showing the child on the wrong side of the fence while having his picture taken by an adult.

And while rhinos are described as docile animals, they still have the potential to inflict serious injury.

Just a child inside the rhino enclosure at @dublinzoo pic.twitter.com/xxsn8Dm5Ag

— Ciarán Ferrie has moved to Mastodon.ie (@ccferrie) July 30, 2016

In May, a gorilla was killed after a child fell into its enclosure in the Cincinnati Zoo.

The incident sparked social media outrage when the gorilla, Harambe, was put down after being seen dragging the boy around its pool.

According to the zoo, tranquillising the gorilla could have left the boy in further danger.

A spokesperson for Dublin Zoo said the incident was currently being reviewed internally.

this man had the child in behind the fence for good 20 minutes ! pic.twitter.com/BzhhUW5Obr

— Adrianna Straszewska (@Adriannasss) July 31, 2016