A report by Amnesty International has revealed that North Korea is trying to cut off its citizens’ connection to the outside world by making calls from private cell phones to international numbers illegal.

The report published on Wednesday said that the Kim Jong-un regime is cracking down on its citizens who are trying to contact their relatives and friends who managed to flee to another country by penalising them. This even includes internment in political prison camps for those caught breaking this law.

“To maintain their absolute and systematic control, the North Korean authorities are striking back against people using mobile phones to contact family abroad,” Yahoo News quoted Amnesty East Asia researcher Arnold Fang as saying.

North Korea is one of the most isolated countries in the world, with its phone and internet connections restricted within its own borders. The North Koreans have no connection to the outside world except for the visiting foreigners.

According to the report, some North Koreans have been able to get hold of illegally imported cell phones to contact their loved ones overseas. Though most phones come from China, all are referred to as Chinese phones, irrespective of their origin. These phones can pick up a Chinese network near the borders.

The most common method to get a hold of a phone is by bribing soldiers hundreds of dollars at the border to get a cell phone and a SIM card or get a broker to set up the call.

The NBC News reported that the Amnesty was told by specialists that the North Korean authorities have employed state-of-the-art surveillance devices to monitor and block such calls.

“To maintain their absolute and systematic control, the North Korean authorities are striking back against people using mobile phones to contact family abroad,” said Fang.

Though speaking to someone abroad is not illegal under North Korean law, it bans the trade of foreign communication devices. Using a Chinese cell phone may tantamount to treason.