Zimbabwe wildlife authorities on Thursday said they suspect ten more elephants succumbed to a bacterial infection that killed 12 young pachyderms last week.  

The latest carcasses were discovered on Tuesday and Wednesday near the northwestern Pandamasuwe Forest, where the previous 12 were found.     

"We now have a total of 22 elephants that have died," parks and wildlife authority spokesman Tinashe Farawo told AFP on Thursday.

"We have taken samples for testing but we suspect they died from the same cause as the 12 that were found dead last week."

Laboratory results suggest the first dozen -- discovered between Hwange National Park and the resort town of Victoria Falls -- were killed by a bacteria.

Park authorities believe the elephants, aged between two and six, were too short to eat leaves from treetops and may have ingested the bacteria by grazing on infected plants.

They ruled out poaching because the animals were found with their tusks intact.

Zimbabwe has more than 84,000 elephants. Scores of elephants have succumbed to starvation and lack of water in recent years.

Others have been poisoned by poachers for their ivory, used to make ornaments and traditional medicine in Asia and the Middle East.

At least 300 elephants died of cyanide poisoning at water holes in Hwange in 2013.

Neighbouring Botswana, home to the world's largest elephant population of around 130,000, lost around 300 elephants early this year. They are thought to have succumbed to natural toxins.