Police said Thursday they have arrested 20 people and booked 10 others without physical detention on charges of selling and using illegal narcotics.

The suspects, including a 51-year-old habitual user, identified only by his surname Ye, allegedly circulated, sold, and used a total of 12 grams of methamphetamines worth 40 million won ($35,000) between December and June, according to the Seoul Metropolitan Police Agency.

In order to avoid the police crackdown, the suspects concealed the methamphetamines in books and electric rice cookers, the agency added.

“Drug trafficking is getting smarter and more covert every day,” a police officer at the agency said, adding that they will strengthen monitoring and intensify their crackdown. The police said they are pursuing six other accomplices with court-issued arrest warrants. (Yonhap News)