BEIJING - The General Administration of Customs (GAC) has busted 724 drug trafficking cases involving about 2.3 metric tons of drugs in the past 17 months, according to an announcement on Monday.

Some 614 suspects were detained during that period, Xu Wenrong, deputy director of the GAC's Bureau of Investigation, told a press briefing ahead of Tuesday's International Day Against Drug Abuse and Illicit Trafficking.

Drug traffickers took advantage of express delivery services to spread their produce from border areas to inland regions. They also made unwitting citizens become drug mules, Xu said.

He noted the anti-drug trafficking mission faced grim conditions, as the crime remains rampant globally and drug traffickers' methods are becoming more covert and varied. However, the customs head promised the GAC would step up cooperation with international anti-drug trafficking organizations.