North Korean authorities have launched another so-called mopping-up operation—a sweeping crackdown—on users of Chinese mobile phones, focusing on regions along the Chinese border. North Korea has once again launched full-scale efforts to block the flow of outside information into the country and internal information to the outside world.

“It feels like state security officers have recently stepped up their crackdowns on users of Chinese mobile phones, focused on Hoeryong, Musan county, Onsong county, and other border regions of North Hamgyong province,” a Daily NK source in North Hamgyong province said recently. “State security officers carrying detectors patrol villages and residential neighborhoods four or five times a day to find signals.”

North Korea has long carried out mopping-up operations against users of Chinese-made mobile phones, which are directly connected to the outside world, denigrating such users as “cancer cells” and regarding them as a prime crackdown target. This is because authorities believe the entry of outside information—or the leaking of domestic information to the outside world—via Chinese-made mobile phones is a significant threat to the regime.

The most recent crackdown on Chinese-made mobile phones that began with the new year followed an order late last year from the Ministry of State Security, which pressed state security agencies in border regions to make their areas free of Chinese-made mobile phones in 2026, noting that “users of Chinese-made mobile phones had yet to be uprooted.”

In response, state security officers in the border region of North Hamgyong province have focused on crackdowns on Chinese-made mobile phone users as their first activity of the new year, the source said.

In Hoeryong, plainclothes state security officers—signal detectors in hand—are often seen patrolling areas that receive Chinese communication signals relatively well.

Expanded detection teams, rotating patrols

“Signal detector teams have been expanded from two to four,” the source said. “The detectors’ detection radius has narrowed, but they still can’t specify the exact signal source, so even if officers find a signal, they often can’t catch the sender. Knowing this, the local Ministry of State Security office has increased detection personnel to narrow the crackdown radius further.”

Detection personnel are assigned to patrol zones, which they rotate every two days. If the same person showed up in the same zone repeatedly, residents would notice and realize that crackdowns were underway in their neighborhoods.

With crackdowns on Chinese-made mobile phones intensifying, state security officers in charge of each district have individually called in people they suspect of using Chinese-made mobile phones or have records of using such phones, employing a mixture of inducements and pressure.

“If a Chinese-made mobile phone user gets caught on a detector, the state security officer for that region is deemed to have failed in his duty,” the source said. “In this context, officers call in residents to seemingly reason with them, getting them to confess that they use the phones.”

The officers try to get users to turn themselves in—if you confess now, nothing will happen to you, they tell residents, but if you miss the opportunity and get caught in a crackdown, you will not be forgiven. “It’s like a cat worrying about a mouse,” the source said. “Ultimately, they’re just trying to get people to confess to boost their numbers.”

Remittance brokers and other people who used Chinese-made mobile phones to make money have temporarily suspended their activities and are lying low to watch the situation unfold.

“This sort of thing happens a lot, and people are used to it, so when crackdowns intensify, people temporarily stop what they’re doing, wait until the crackdowns end and restart what they were doing,” the source said. “So, people say that intensifying crackdowns has the opposite effect of making Chinese-made mobile phone users harder to find.”

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