Around 400 buffaloes drowned after stampeding into the Chobe River along the border between Botswana and Namibia, possibly while running away from lions, officials said.
The Chobe river flows along the northeastern border of the Chobe National Parks, which is known for the large breeding herds of elephants, giraffes, sable and the African buffalo, making it a major tourist destination in Southern Africa.
Initial investigation in Botswana and Namibia suggest that an exceptionally large herd was grazing in Namibia before they stampeded into the river on Tuesday night.
Namibia’s environment minister Pohamba Shifeta told AFP news agency that the incident, though “unfortunate”, was due to natural causes.
About 1,000 buffaloes had struggled to get over a river bank when the stampede started, he said, adding that three lions were seen in the area.
“The cause of the stampede is still uncertain and under investigation. However, initial indications are that they were being chased by a pride of lions,” a Botswana ministry statement said.
The ministry added that, despite the number of animals involved, this was “not an unusual occurrence” in the area, with mass drownings reported to have happened before in the Chobe river.
The meat from the dead animals is being donated to local communities, officials said.