BEIJING -- Chinese authorities Friday destroyed 662 kilograms of ivory that was seized after being smuggled into the country, as part of a crackdown on the illegal trade.

In front of reporters in a suburban section of Beijing, wildlife officials placed raw tusks and ornate carvings onto a conveyor belt that fed the ivory into a machine that crushed the pieces into tiny pebbles.

China bans smuggling of ivory, but in 2008 secured an exemption to a global ivory trade moratorium to import legal stockpiles for traditional carvings that can be sold domestically. Conservationists argue that this legal trade has prompted a resurgent demand for ivory while providing a convenient cover for a thriving black market. They have demanded China impose a complete ban on imports and domestic trade.

China announced a temporary, one-year ban on all imports in February, saying that would allow authorities to gauge the effect on poaching.