China customs has smashed a smuggling ring attempting to ship nearly 1 million metric tons of refined oil valued at an estimated $770 million.
Authorities said Wednesday that the ring was likely one of the largest in the country.
Authorities seized 11 ships and arrested 171 people in a joint operation. Customs officers from the port of Ningbo, local law enforcement and maritime police joined in the raids in eight China regions.
The officers raided ports in Jiangsu, Fujian, Shandong and Zhejiang. The General Administration of Customs said it identified 14 gangs.
They didn't say if the oil was being transported into or out of the country. China is Asia's largest consumer of oil and the region's largest refiner.
Customs said the raids were the "most extensive operations" conducted and were a big win in the effort to crackdown on refined oil smuggling along the southwest coast.
Analysts said smuggling of refined oil was a problem because it disrupts the region's retail fuel market. Smugglers are a safety hazard owing to the lack of regulation.
Compared with legally bought and sold refined oil, smuggled products are of inferior quality. Customs said smuggled products, particularly gasoline and diesel, have sulfur contents that exceed limits.
Customs has been concentrating on hot spot areas such as the Yangtze River delta and the Pearl River. Since the campaign was launched, the agency said it had recorded 170 separate cases with a value of 5.4 billion yuan ($830.5 million).
