Tests conducted in Zimbabwe so far point to a disease called haemorrhagic septicaemia, which is caused by bacterial infection, he said.
Rangers have ruled out cyanide poisoning or poaching because the animals were found with their tusks intact.
Mangwanya said wild animals are more susceptible to disease during the country’s dry and hot season, which is roughly from August to November.
In recent years Zimbabwe has suffered through successive droughts made more severe by global warming, leaving animals with less water and vegetation.
Samples have been sent to a laboratory in Britain and others will be dispatched to South Africa and the United States for further tests and analysis.
Zimbabwe counts more than 84,000 elephants — almost double the southern African country’s ecological carrying capacity of between 45,000 and 50,000.
Neighbouring Botswana, home to the world’s largest elephant population of around 130,000, lost around 330 elephants early this year from cyanobacteria poisoning.