The lifeless body of a man was found in a bear cage Sunday in the Belgrade Zoo, an official said.

Zoo employees found the body during a routine check of the cage, which has no roof, Belgrade emergency service doctor Nada Macura said, without giving details.

The Beta news agency, citing doctors, said the man was 22 years old and had injured his head, abdomen and legs, but that it was not immediately clear if the injuries were sustained from the fall or were inflicted by the animals.

The Belgrade Zoo is located within the ancient Kalemegdan fortress in the city center.

A restaurant is located just above the zoo, and thousands have visited the fortress this week for a beer festival. Local media speculated he might have fallen off a wall into the bear enclosure during the night.