North Korea is blocking SIM cards to prevent its citizens from contacting overseas countries, according to testimony from North Koreans collected by the Daily NK website.
Authorities have blocked a number of roaming services and intensified their efforts to seize Chinese mobile phones in the border areas, according to the Daily NK, which is headed by North Korean defectors and known to have contacts within the hermetic country .
The measure centers on the numbers of Koryolink (the only national mobile operator) starting with 191, because they correspond to many of the cards that were sold a few years ago to foreigners who visited the country offering roaming and are still in circulation.
The sale of these numbers has been banned in border regions with China, from where the phones can be connected to the networks of the neighboring country and make calls to China itself or to South Korea, detailing the web a source from Pyongyang.
Another testimony of a resident of North Hamgyong (border province with China) indicates that even so the North Koreans are trying to avoid this blockade, since many buy on the black market cards 191 that have been sold in Pyongyang (where it is not prohibited for sale).
It is believed that more than three million North Koreans own mobile phones contracted with Koryolink, company originally participated by the Egyptian Orascom that launched the first 3G network in the country in 2008.