HARARE, Zimbabwe (AP) — A bacterial infection, possibly from eating poisonous plants, could be the cause of the death of 11 elephants in a forest in western Zimbabwe, a parks agency spokesman said Tuesday.

The carcasses of the elephants were discovered last week in Pandamasue Forest, located between Hwange National Park and Victoria Falls.

“Food is scarce during this dry season. There is an overpopulation of the animals, so the young ones tend to eat anything and some of the plants are poisonous. It could be a bacterial infection, but we still need to prove it. The scientists are at work,” said Tinashe Farawo, spokesman of the Zimbabwe National Parks and Wildlife Management Authority.

The dead young elephants were found with the tusks still on their bodies, ruling out poaching. In recent years poachers in Zimbabwe have poisoned dozens of elephants with cyanide and then have taken their ivory tusks to sell them to illegal traders.

Investigations will also try to establish if there is a link between the deaths and those reported in neighboring Botswana.

Scientists are still investigating the deaths last month of more than 275 elephants in Botswana’s Okavango Delta area. Poaching, poisoning and anthrax have also been ruled out in those deaths.

Botswana has the world’s largest elephant population, estimated at 156,000 and Zimbabwe has the second largest, estimated at 85,000. Last year about 200 elephants in Zimbabwe died of starvation as a result of the country’s drought.

Zimbabwe argues that it should be allowed to sell some of its elephants to foreign zoos to ease congestion and also raise more money for conservation.