Elephants and rhinoceroses are being slaughtered to the point of possible extinction by heavily armed African rebels and militias who use profits from the illegal poaching and sale of ivory to fund wars across the continent, conservationists say.

The groups include the Islamist al-Shabaab of Somalia; the Janjaweed tribal warriors of Sudan and the Lord's Resistance Army of Uganda who have turned the savannah of central and southern Africa into what the German newsmagazine Der Spiegel calls "a Killing Fields for elephants."

Tom Cardamone, an expert on the illegal ivory trade, told a U.S. Senate hearing in September, "In recent years, organized crime syndicates, militias and even terrorist elements have taken notice of the profits that can be made in the illegal trafficking of wildlife."

This, he declared, is "generating an alarming uptick in the scale of the industry and posing serious national security concerns for the United States and our partners."

One kilogram -- 2.2 pounds -- of ivory can fetch up to $2,000 on the black market, particularly in China and Thailand.

A single elephant tusk can weigh up to 130 pounds, meaning one full-grown bull elephant is worth up to $120,000 to poachers who outgun national park rangers and even police units sent against them.

There are an estimated 500,000 elephants in Africa but the poacher gangs and their high-powered automatic weapons reportedly kill tens of thousands a year. That's the worst slaughter since the 1980s.

Ugandan troops, operating illegally, reportedly hunt from army helicopters, wiping out entire herds.

Customs officials in Malaysia recently seized 1,500 elephant tusks, 24 tons of ivory, hidden in China-bound containers. It was the biggest illegal ivory haul ever, roughly equivalent to all the poached ivory seized in 2011.

In October, Hong Kong authorities uncovered 1,000 pieces of poached ivory from Tanzania.

The World Wildlife Fund reports that poachers from Chad and Sudan armed with assault rifles and rocket-propelled grenades killed at least 100 elephants in Cameroon's Bouba N'Djida National Park.

The WWF has warned the United Nations the illegal ivory trade threatens African governments as rebel forces used the proceeds to fund their wars.

"This is about much more than wildlife," said Jim Leape, director general of WWF International. "This crisis is threatening the very stability of governments. It has become a profound threat to national security."

Rhinos, too, are being hunted in a poaching epidemic that is threatening the species.

South Africa's Environmental Affairs Department disclosed this month that at least 633 rhinos have been slaughtered this year by poaching gangs. It said 395 of the killings took place in the Kruger National Park in the republic's northeast.

That's a massive increase. Throughout the 1990s and up until 2007, the number of rhinos slain by poachers averaged 15 a year.

The main reason behind the huge surge in the slaughter of both species is a seemingly insatiable demand for ivory and rhino horn in increasingly affluent Asian states, particularly China.

There's a thriving black market in Thailand, too, but China, which has a legal ivory market that's supposed to tightly controlled but isn't, is indisputably the key market for poached ivory.

Ivory is widely prized in the Orient and ground-up rhino horn is considered an aphrodisiac and a cure for many diseases, although there's no medical evidence to support that.

Ninety percent of the illegal ivory ends up being smuggled to Asia, where conservationists say ineffective enforcement of international trafficking of ivory and official corruption aids the smugglers.

Conservationists say tens of thousands of Chinese working on development projects in Africa, as Beijing acquires energy and mineral resources across the continent, are being used in ivory and rhino horn smuggling operations.

Some shipments are taken into the war-ravaged Democratic Republic of Congo, where they're funneled out with illegal minerals such as copper, iron and tin ore plundered by warring groups in Africa's largest country.

Famed British conservationist Jane Goodall made an impassioned plea this month for a worldwide ban on ivory sales to prevent the African elephant becoming extinct.

"A massive tragedy is unfolding in some parts of Africa," she said. "This is desperately serious. We believe Tanzania's lost half its elephants in the last three years. Armed militias are now shooting the elephants."