HOHHOT -- Four people, including two Russians, have received prison terms for smuggling 213 bear paws from Russia to China, the largest amount ever seized by Chinese customs.

The Intermediate People's Court in Hulunbuir City, Inner Mongolia autonomous region, sentenced Chinese defendants Lyu and Jin to seven years and six years in prison respectively, and fined 300,000 yuan (about $48,000) each for smuggling animal products, a court spokesman told Xinhua on Tuesday.

The Russians were sentenced to five years apiece.

On May 22 2013, customs officials in the Inner Mongolian border city of Manzhouli found the paws, from at least 63 brown bears, in tires of a van attempting to enter the city.

Authorities in China and Russia have been working on bear paw smuggling in recent years, but there is still a strong demand for the animal parts, seen as a delicacy in China. Smuggled bear paws from Russia, whose dense forests are home to large numbers of brown bears, are actively traded in the black market in China. The illegal trade is highly lucrative. Paws costing 400 yuan per kg in Russia can be sold for 20 times that in China, said a Manzhouli customs official.

Bears are listed by the Chinese government as a protected species.