JINAN, Dec. 29 (Xinhua) -- Over 6,400 suspects were arrested in 6,113 drug-related crimes in 2017 in eastern China's Shandong Province, the provincial public security bureau announced Friday.

Shandong has seen drug crime rise in recent years. More than 20,000 drug cases were uncovered in the past three years, and the number of registered drug addicts in the province exceeded 100,000, according to Ding Guanyong, deputy chief of the bureau.

In one case, police seized 15 tonnes of raw materials used to produce methamphetamine, methcathinone and other narcotics, which surpassed the volume of drug materials seized in the past decade combined. Over 110 suspects were arrested, with 5 million yuan (0.8 million U.S. dollars) and 40 vehicles confiscated in the case.

Ding said new methods to manufacture, smuggle and distribute narcotics constantly emerged and local police would intensify efforts to fight against drug crimes.