PLEASE NOTE: CONTAINS GRAPHIC MATERIAL
Toxins produced by bacteria found in water have been blamed for hundreds of mysterious elephants deaths in Botswana.
A news conference on Monday (September 21) heard that the number of dead elephants had risen from 281 in July to 330, and that neurotoxins produced by the water-dwelling cyanobacteria had been detected.
But Mmadi Reuben, the principal veterinary officer at the Department of Wildlife and National Parks, said several unanswered questions remained - such as why it was only elephants that died, and why they were concentrated in one particular area.
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 to around 130,000.
At the end of last month neighboring Zimbabwe found more than 20 dead elephants near the country's biggest game park with authorities there suspecting they had succumbed to a bacterial infection.