An investigation has been launched after 11 elephants were found dead in a forest.
The bodies were discovered by park authorities in Pandamasue Forest in Zimbabwe, with no clear sign of what killed them.
Poaching was ruled out because the elephants’ tusks were still on the bodies. Poachers are known to poison the animals in the area to sell their ivory tusks to traders.
Spokesman for the Zimbabwe National Parks and Wildlife Management Authority, Tinashe Farawo, said blood samples of the bodies were taken to a laboratory to determine the cause of their deaths.
He added: “We can only ascertain the cause of death after the tests. But we have ruled out cyanide poisoning.
“Only elephants were affected. No vultures or any other animals were affected.”
Mysterious deaths of elephants in Africa have been common in recent months.
More than 280 elephants in Okavango Delta, in the southern African country of Botswana, died from a mystery virus, although conservationists fear the actual death toll could be closer to 400.
Researchers have reported seeing elephants looking confused, wandering in circles and falling onto their faces before dying, Daily Express reports.
Wildlife experts believe an unknown pathogen – a novel elephant virus – could be behind the mass deaths.
Poaching and anthrax have been ruled out as possible causes and there has been no drought, another mass killer of elephants.
The deaths have been concentrated in an area of more than 3,000 square miles in Botswana’s Okavango Delta which is home to about 18,000 elephants.
Niall McCann, director of conservation for the charity National Park Rescue, said: “We are currently living with a zoonotic spillover event.
“The absolute worst case is that this could turn into another one. It is incredibly important to rule out the prospect of this crossing over into people.
“Yes, it is a conservation disaster – but it also has the potential to be a public health crisis.
“The whole environment needs to be sampled — the vegetation, water and soil. All the tissue of the carcass, the muscle, blood, brain, spleen.”
Although the number of deaths so far represents a fraction of the estimated 130,000 elephants in Botswana, there are fears more could die if authorities cannot establish the cause soon.
Oduetse Kaboto, a senior official in the environment and tourism ministry, said: “We have to wait for another set of results and reconcile the two to see if they are saying the same thing before we come to a definitive conclusion
“We are hoping the second set of results will come in next week and that’s when we should be able to communicate to the public the cause of deaths.”
Dr Cyril Taolo, acting director for Botswana’s department of wildlife and national parks, said: “We are aware of the elephants that are dying.
“Out of the 350 animals we have confirmed 280 of those animals. We are still in the process of confirming the rest.”
Africa’s overall elephant population is declining due to poaching, but Botswana, home to almost a third of the continent’s elephants, has seen numbers grow from 80,000 in the late 1990s.