Botswana says it’s received its first test results on Friday from samples sent to Zimbabwe to determine the mysterious cause of death of hundreds of elephants.

But it’s awaiting more results from South Africa before making the findings known.

They have ruled out poaching and anthrax.

Botswana wildlife officials say they’ve found six more elephant carcasses near the Okavango Delta, bringing the total to 281.

The deaths were concentrated in an 8 000  square kilometre area, and is home to about 18 000 of the animals.

While the dead only make up a small fraction of Botswana’s estimated 130 000 elephants, there are fears that more could die if authorities can’t establish the cause of death soon.