Eight suspects have been arrested for smuggling about 20,000 tonnes of solid waste, said Shijiazhuang customs of north China's Hebei Province.
The customs said the suspects purchased waste plastics and scrap metal in the United States and Canada, and imported them using invalid permits via ports in Tianjin and Guangzhou before reselling to domestic buyers for profit starting in May 2016.
In December, Shijiazhuang customs sent 48 anti-smuggling police officials to several Chinese cities and arrested eight suspects, detaining about 20,000 tonnes of solid waste so far.
The customs seized a total of 2,362 tonnes of imported waste plastics and 2,225 tonnes of scrap metal in nine separate cases from January to November 2017.