China has destroyed about six tonnes of illegal ivory in its stockpile.

It’s an unprecedented move wildlife groups say shows growing concern about the black market trade by authorities in the world’s biggest market for elephant tusks.

Authorities on Monday displayed a pile of ornaments, carvings and tusks to reporters before feeding them into two crushing machines.

Forestry and customs officials organised what they said was the country’s first large-scale ivory destruction in Dongguan in southern Guangdong province. That’s where much of China’s ivory trade is focused.

Conservation groups say China is the world’s biggest market for ivory.

Demand is fuelled by rapid growth in the world’s second biggest economy, which has created a vast middle class with the spending power to buy ivory carvings prized as status symbols.