(NSA) – The use of cellular phones in North Korea has been officially prohibited since May 19, according to a North Korean official from the National Security Agency (NSA) who has been in close contact with the Democracy Network against North Korean Gulag. This prohibition resulted from a special directive given by the National Defense Committee. The investigation of the Ryongchon train explosion on April 22 led the NSA to believe that special groups were involved in plotting the explosion. They also discovered that these groups used cellular phones to communicate and to organize this alleged “criminal act,” and the NSA concluded that this explosion had been plotted in advance. After the investigation, the NSA asked Kim Jong Il to order the prohibition of cellular phones, as their use was believed to promote the spread of information and the collapse of the society. Cellular phone users in North Korea , including sources in Pyongyang , have expressed dissatisfaction with the prohibition. Citizens were required to pay about US$1300 for each cellular phone, including a registration fee, but none of the users have received compensation for the government-imposed ban. Many sources in North Korea continue to believe the Ryongchon train explosion was part of a plot to kill Kim Jong Il.