BEIJING - Nantong customs in east China's Jiangsu province has ordered the shipping back of 4,003 tonnes of smuggled solid waste to where it originated, according to the General Administration of Customs.

Disguised with fake documents, the garbage consists of slags produced from the making of iron ore pellets and was seized during an inspection in March 2018. The import of such materials is banned in China.

China began importing solid waste as a source of raw materials in the 1980s and for years has been the world's largest importer, despite its weak capacity in garbage disposal. Some companies have profited by illegally bringing foreign waste into the country, posing a threat to the environment and public health.

As part of its anti-pollution efforts, the government decided to phase out and halt such imports by the end of 2019, except for those containing resources that are not substitutable.