Washington - An industrial rock crusher destroyed 6 tons of illegal elephant ivory in the US state of Colorado on Thursday, as the government said it wanted to send a message about the plight of African elephants and other species poached for their tusks.The United States "will not tolerate wildlife crime that threatens to wipe out the African elephant and a host of other species around the globe," the US Fish and Wildlife Service said.The agency - a bureau within the Department of the Interior - said the ivory was estimated to have come from the slaughter of more than 2 000 elephants. It included tusks, carvings, statues, ceremonial bowls, masks, jewellery and ornaments. It was confiscated from smugglers over the last 25 years.Tens of thousands of elephants are killed each year for their tusks, and global trade in ivory is estimated to be worth $10bn.Prior to being seized, most of the ivory crushed into gravel-size pieces on Thursday was destined to be sold illegally in the US or overseas, the agency said.‘Horrific slaughter’Dan Ashe, director of the Fish and Wildlife Service, said much of the world's trade in wild animal species - both legal and illegal - is driven by US consumers, making the US part of the problem. Therefore, "we have to be part of the solution," he said.Many populations of elephants have shown recent signs of recovery, but rising demand for ivory is fuelling a "horrific slaughter of elephants in Africa, threatening remaining populations across the continent," said Secretary of the Interior Sally Jewell.The Fish and Wildlife Service said "well-armed and organised criminal enterprises" have taken advantage of insufficient protection of the animals in remote areas. US news reports said the Islamist al-Shabaab militia, an al-Qaeda-affiliated group, has been linked to the illegal trade.Carter Roberts, chief executive of the World Wildlife Fund, noted that Gabon, Kenya and the Philippines have also held ivory crushing events in the past, and he encouraged other countries to do the same.African elephants are listed as threatened under the Endangered Species Act and are protected under the African Elephant Conservation Act.The ivory fragments left by the crusher will be stored temporarily at a Fish and Wildlife Service repository. The agency said it hoped to find ways to use the fragments to increase awareness of poaching.