By TENDAI MUSIYAHWANGE, Zimbabwe (AP) â¿¿ The stench of rotting elephant carcasses hangs in the air in western Zimbabwe, where wildlife officials say at least 91 elephants were poisoned with cyanide by poachers who hack off the tusks for the lucrative illegal ivory market. Massive bones, some already bleached by the blistering sun in the Hwange National Park, litter the landscape around one remote watering hole where 18 carcasses were found. Officials say cyanide used in gold mining was spread by poachers over flat "salt pans," also known as natural, mineral-rich salt licks. They say lions, hyenas and vultures have died from feeding on contaminated carcasses or drinking nearby. "The magnitude of what we are witnessing today is much higher than what has occurred previously," environment minister Saviour Kasukuwere told reporters on a trip to the park Monday. Cyanide attacks the bloodstream, kills almost instantly and causes rapid decomposition. Most of the poisoned elephants died in the past month. The chemical is commonly used by illegal gold panners to separate the metal from surrounding ore and is easily available. Nine suspected poachers have been arrested this month after the biggest, most brutal poaching spree on record. Three men were sentenced to up to 16 years in jail. The Hwange park, stretching over 14,000 square kilometers (5,400 square miles), has one of the highest concentrations of elephants in Africa. Kasukuwere, newly appointed to the environment ministry after disputed elections won by longtime President Robert Mugabe in July, said Zimbabwe will intensify efforts to campaign among world nations â¿¿ including Asia, where there is the highest demand for ivory â¿¿ to curb a trade declared illegal by the Convention on International Trade in Endangered Species. Tusks of the poisoned elephants are thought to have been smuggled into neighboring South Africa through illicit syndicates that pay desperately poor poachers a fraction of the $1,500 a kilogram (2.2 pounds) that ivory can fetch on the black market.