North Korean authorities have stepped up their surveillance of citizens believed to be drug users by interrogating their children in schools, employing an old reviled method of weeding out drug users that had been discontinued by former leader Kim Jong Il, sources inside the country said.

“Security officials in charge of schools are intimidating and interrogating elementary school students to investigate drug offenses, and their parents have been immensely shocked about it,” a source in South Hamgyong province told RFA’s Korean Service.

During one such period of intensive investigation of local drug use, a security official in Sapo district of Hamhung, capital of South Hamgyong province, drew pictures of paraphernalia for injecting drugs on the board in an elementary school and asked the seven-year-old students in the class what they were, the source said.

The security official from the country’s state security department, which is similar to the U.S. Central Intelligence Agency, recorded the names of all the students who responded with “konapal” or “koggiri,” Korean slang words for drug paraphernalia. He called them up one by one to ask them how they knew the names of the items, the source said.

As the security official cajoled and threatened the students into giving him information, many of them admitted that their parents used drugs. Their parents were then arrested on drug offenses, the source said.

The state security department’s use of children to crack down on adults has infuriated many citizens, sources said.

“All residents in people’s units are forced to anonymously turn in materials relevant to drug offenses,” a source in North Hamgyong province told RFA. “Kim Jong Un’s regime has resurrected the method of investigation which [former leader] Kim Jong Il suspended because of worries about public disaffection.”

“Now anonymous investigations are only focusing on drugs, but they likely can be extended later,” the source said. “North Korean residents are at odds, suspecting each other because of the anonymous investigations of drug offenses.’

“The state security department has taken the lead in instigating social conflicts,” he added.

State security agencies under former leader Kim Jong Il employed such methods to try to eradicate drug smuggling into the isolated country.

Authorities ordered citizens to anonymously write the wrongdoings of their coworkers or members of people’s units, a state control mechanism that consists of 20-40 households, using various techniques to solicit information, including the intimidation and conciliation of children.

During that time, only state security units organized by North Korean authorities applied such methods as a means of curbing social unrest and citizen antipathy towards the regime, sources said.

North Korea has in recent years grappled with a drug addiction problem among youth, workers and even police officers, with the powerful stimulant methamphetamine or “ice” as their primary drug of choice.

Long seen as a supplier of the highly addictive drug to China, North Korea experienced an influx of methamphetamines after its neighbor started cracking down on cross-border smuggling.

Reported by Jieun Kim of RFA’s Korean Service. Translated by Yunju Kim. Written in English by Roseanne Gerin.