Experts at a zoo in the Moroccan capital are trying to understand why an elephant hurled a stone in the direction of visitors, killing a seven-year-old girl.

The behaviour of the female elephant was "abnormal" and needs to be examined, a vet at the zoo in Rabat said.

The girl was at the Zoological Garden of Rabat with her family on Tuesday, admiring three elephants, when one picked up a stone and tossed it more than 10 metres over a large ditch and a wooden barrier toward the visitors. The girl was hit on the head and died hours later.

The elephant exhibit has been temporarily closed, vet Abderahim Salhi said, adding that the zoo's employees remained in shock three days after the "unforeseeable accident".

"The behaviour ... of any animal is very complex, and wild animals are unpredictable. We are all surprised. We don't yet understand."

The zoo, which opened in 2012 on the edge of Rabat, was designed to show animals living in replicas of their natural habitat - but with no direct contact with visitors, Mr Salhi said.

Stones are plentiful inside the elephant habitat, as they would be in natural surroundings.

Salma Slimani, in charge of zoo administration, said: "We are very sad at what happened, but it would be wrong to blame the elephant. This was not premeditated."