Tons of discarded clothes smuggled from overseas are piled up at Tuyang port in Shenzhen on Thursday. [Photo by Zhou Mo]

Nearly 450 out of 1,046 tons of discarded clothes smuggled from overseas were transported for incineration from Tuyang port in Shenzhen on Thursday in Shenzhen Customs' latest crackdown on solid waste smuggling.

Customs also arrested six suspects involved in the case, including one Taiwanese.

The 441 tons of waste were first seized by the Shenzhen border force on Sept 4 on a vessel from Hong Kong, where they were loaded, Wang Mingwei, an anti-smuggling official from customs, said.

The vessel was originally bounded for Taiwan, but the suspects changed the route on the way and drove the vessel into the Shenzhen sea area where it was seized, he said.

The illegal items and suspects were then sent to Shenzhen Customs for investigation.

In a separate case in June, 605 tons of smuggled discarded clothes were seized. The waste was burned in August.

The two cases are the biggest in terms of the amount involved over recent years, customs said.

According to a suspect, the discarded clothes were mainly collected from Japan and South Korea and were intended to be sold to the mainland market. Officials said the exact destination is yet unknown, as the case is still under investigation.

"We attach high importance to the disposal of the solid waste," said Chen Lei, deputy head of division of accounting at Shenzhen Customs, who is in charge of the matter.

"Stains can obviously be seen on some of the clothes, which may cause serious harm to the environment and people's health. We are making all our efforts to supervise the disposal process to ensure th waste does not enter the market," Chen said.

Solid waste includes electronic waste, household garbage, discarded clothes, construction waste and so forth. Smuggling of more than 5 tons of waste is seen as a serious case and smugglers can be held criminally liable.