Poachers are slaughtering Tanzania's elephants for their ivory at such alarming rates that the population could be completely wiped out in just seven years, conservationists told a conference Friday.

The two-day UN-backed conference, which opened Friday, aims to develop strategies to stem elephant poaching in Tanzania, a top safari destination determined to protect its prized wildlife but struggling to stop sophisticated organised criminal gangs.

"Approximately 30 elephants a day are killed... at this rate the population will be exterminated by 2020," said the Tanzanian Elephant Protection Society (TEPS), an independent conservation group.

Tanzanian Vice President Mohamed Gharib Bilal painted a bleak picture as he opened the summit, asking for international assistance in battling the increasingly well-organised and equipped poaching gangs.

"Organised and intricate poaching networks in and outside the country sustain this illegal trade, thus making it difficult for Tanzania alone to win this battle," Bilal said.

Tanzanian police late last year launched a crackdown on suspected poachers amid a spate of elephant and rhino killings, operating under what was reported to be a shoot-to-kill policy and making sweeping arrests.

While poaching rates dropped drastically, the operation was shut down because of allegations of harassment, rape and murder of suspected poachers.

At least 19 people were killed and over 1,000 arrested in the crackdown, according to a government investigation. Once it stopped, elephant killings soared again.

- 'Needs long-term commitment' -

TEPS director Alfred Kikoti said he wanted the military to resume its role battling poachers.

"They have to stay in there, protecting our elephants," he said. "They can't just be in there for one operation and then pull out. It needs to be a longer term commitment."

Poaching has risen sharply in Africa in recent years, with gangs targeting rhinos and massacring whole herds of elephants for their ivory.

Organised gangs with insider knowledge and armed with automatic weapons and specialised equipment such as night vision goggles, use chainsaws to carve out the rhino horn or remove elephant tusks.

The growing trend is threatening Tanzania's tourism sector, a key foreign currency earner for the country.

The industry, nine tenths of which revolves around wildlife, accounts for 17 percent of Tanzania's gross domestic product and employs over 300,000 people, according to official statistics.

Millions of dollars of elephant tusks and rhino horns are smuggled out of East Africa each year, according to the United Nations, with demand fuelled by an increasingly affluent Chinese middle class.

Tanzania's vast Selous-Mikumi region was once home to one of the largest elephant populations in the world, with around 70,000 animals living there in 2006, Bilal said.

Last year, that had plummeted to only 13,000 elephants.

The sale of ivory stockpiles -- from tusks seized from poachers or recovered from animals that have died naturally -- to raise funds for conservation created fierce debate at the conference.

International trade in ivory has been banned under the Convention on International Trade in Endangered Species of Wild Fauna and Flora (CITES) since 1989.

Tanzania's current stock of 120 tonnes of ivory could -- if sold at black market prices -- raise over 60 million dollars (43 million euros), but conservationists argued it would only encourage more killings.

"A legal ivory market only stimulates an illegal ivory market," said Trevor Jones, director of the Southern Tanzania Elephant Project.

"Moreover, an existing stockpile stimulates poaching, because it gives poachers hope that there may one day be a legal market, giving criminals a chance to launder their ivory."