More than 600,000 drug addicts underwent compulsory detox in rehabilitation centers between 2011 and the end of June, and 30 percent of them have overcome their addiction, the Ministry of Justice said.

More than 200,000 drug addicts are receiving treatment in the centers run by local justice departments, according to the ministry, including 5,000 who took drugs again after being discharged.

"It's easy for their bodies to get rid of the drug, but it's more difficult for them to get off the drugs psychologically," said a senior ministry official who declined to be named, adding that 70 percent of users take drugs again after they are rehabilitated and discharged.