BEIJING — China has seized more than 2,700 ivory tusks in what customs authorities are calling the country’s biggest smuggling case in years.

China’s Customs Administration announced Monday that it confiscated nearly 7.5 tons (6,803 kilograms) of ivory on March 30. The illicit goods came from an international criminal group that has been smuggling ivory for some time, authorities said, noting that 20 suspects are now in custody.

“We have a zero tolerance policy when it comes to smuggling ivory tusks, as well as other products from endangered species,” Customs Vice Minister Hu Wei said at a news briefing.

Since the start of the year, customs officers have seized a total of 8.5 tons (7,711 kilograms) of ivory products through 53 investigations. An additional 129 cases involved the smuggling of other endangered animal products, including pangolin scales, shark fins and turtle shells.

The ivory seized on March 30 came from Nigeria and other African countries, said Sun Zhijie, head of the administration’s anti-smuggling bureau. It was shipped across multiple countries, hidden in cargo containers of wood and kept in an old Chinese waste factory while the suspects prepared to sell it, Sun said.

China has cracked down on smuggling in recent years and implemented in 2018 a total ban on all trade in ivory products. The ban does not cover the semiautonomous port of Hong Kong, which remains a major transit point for endangered species products and other contraband. The financial center is now working toward a complete ban on the local ivory trade, slated to take effect by 2021.

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