Botswana is investigating a growing number of unexplained deaths of elephants, having confirmed 275 had died, up from 154 two weeks ago, the government said on Thursday.
The dead elephants were first spotted months ago in the Okavango Panhandle region, and the authorities say they have since been trying to discover the cause. Poaching has been ruled out as the cause of death, as the carcasses were found intact.
"Three laboratories in Zimbabwe, South Africa and Canada have been identified to process the samples taken from the dead elephants," the Ministry of Environment, Natural Resources, Conservation and Tourism said in a statement.
In a report prepared for the government and seen by Reuters, Elephants Without Borders (EWB), a conservation organisation, said that its aerial surveys showed that elephants of all ages appeared to be dying. The group counted 169 dead elephants on May 25, and another 187 on June 14, according to the report.
The directors of EWB did not immediately respond to phone calls or text messages seeking comment on the report.