TIANJIN, Aug. 25 (Xinhua) -- The customs in north China's Tianjin Municipality have seized more than 2,000 tonnes of smuggled solid waste, the customs said Tuesday.

The solid waste - industrial residue containing zinc - was smuggled in from Mexico and Malaysia, according to the customs. China bans the import of such solid waste.

Five suspects involved in the case have been placed under "criminal compulsory measures," and further investigation is underway.

China began importing solid waste as a source of raw materials in the 1980s. Given rising public concerns over environmental pollution and China's green development drive, the country decided to phase out and halt such imports by the end of 2019, except for those containing resources that are not substitutable.