Harare, Oct 16 (IANS): Zimbabwe's National Parks and Wildlife Authority Tuesday said more than 100 elephants were killed by poachers using toxic cyanide in one of Africa's prime elephant sanctuary over the past two months.

The elephant death toll had reached 90 more than a week ago but authorities found a dozen more carcasses in a site some 38 km from the main camp in the sprawling Hwange National Park over the weekend, Xinhua reported.

The mass poisoning is suspected to have been conducted by a second poaching ring, officials with the wildlife authorities said.

So far, 13 elephant tusks were recovered and two suspects -- both impoverished villagers -- were arrested, the officials said.

While in the past poachers used rifles to down the jumbos to hack off their tusks, more cases of poisoning have emerged in which poachers dose deadly cyanide in the watering holes where thirsty elephants commonly drink water during the dry season that runs from May to November.

Conservationists say this kind of poaching is "cruel" as it kills not just elephants but animals in the entire food chain. In the latest poisoning case, eight vultures -- the first predators at the kill -- were also found to be poisoned to death.

Three of the poachers who conducted the poisoning had been sentenced to 16 years in prison but the mastermind of the poaching syndicate -- believed to be a South African businessman -- remains on the run.

Zimbabwe is home to about 120,000 African elephants, and 40 percent of them live in Hwange, the third largest national park in Africa.