China customs recently seized 2,748 ivory tusks weighting a total of 7.48 metric tons after cracking down on a major smuggling case in a joint operation.

Tusks are illegally transferred from African countries and imported into China under the guise of "wood", officers from the General Administration of Customs said on Monday.

The smuggling case was cracked on March 30 after a joint operation lasting three months. The action was conducted under the cooperation of police forces from several cities including Hefei, Nanjing, Beijing, Fuzhou and Qingdao.

Twenty suspects were detained for further investigation, according to Sun Zhijie, director of the administration's anti-smuggling bureau.

The haul is the largest seized in anti-smuggling actions conducted by the administration independently, according to Sun.

He said most tusks were hidden in an abandoned factory by the gang.

According to Hu Wei, deputy director of the administration, stronger effort has been made by customs this year to stop smuggling of wildlife and related products online.

So far, customs has seized more than 100 tons of endangered wildlife and byproducts this year, of which about 300 kilograms were ivory tusks and byproducts.

Statistics released by the administration on Monday show a total of 182 smuggling cases on endangered wild species were solved since early this year. More than 500 tons of wildlife were caught.

Among all smuggling cases this year, 53 were related to ivory tusks and products, with a total of 8.48 tons of product involved. Twenty-seven smuggling gangs were detained.