North Korean leader Kim Jong Un has restored the once-suspended practice of surveying and interrogating children about whether their parents are drug users, Radio Free Asia reported Thursday. The country has struggled in recent years to quell a surge of addiction to methamphetamines, and it appears security officials are now cracking down by attempting to use children as sources.

In one elementary school in the city of Hamhung, an official drew pictures of drug paraphernalia and presented them to seven-year-old students. Those who could identify or name the tools were called up to ask how they had acquired such knowledge. The official then "cajoled and threatened" those students, many of whom confessed that their parents were drug users. Officials subsequently arrested those parents.

“Security officials in charge of schools are intimidating and interrogating elementary school students to investigate drug offenses,” an anonymous source told Radio Free Asia.

The method is similar to the Orwellian practice employed during the reign of Kim Jong Il, the father of Kim Jong Un, where North Koreans were ordered to anonymously submit wrongdoings of colleagues or others they knew. But those efforts were primarily geared toward culling out people opposed -- or indifferent -- to the North Korean regime. That system of pitting neighbor against neighbor was suspended, however, because of its unpopularity.

North Korea produces some of the most pure crystal meth in the world, VICE News reported in April 2014. The country began manufacturing it in the early 2000s in order to generate income, and both heroin and meth from North Korea have been distributed to China, Japan and the United States.

In 2005, the country reportedly attempted to cut down on meth production and distribution, or at least it did so officially, according to VICE. The drug then became available primarily to people within North Korea, all but ensuring that its use domestically would soar and setting the stage for a wave of addiction.