North Korean leader Kim Jong Un speaks at the seventh Congress of the Workers' Party of Korea in this undated photo released by North Korea's Korean Central News Agency in Pyongyang, May 10, 2016. Reuters/Korean Central News Agency

North Korean leader Kim Jong Un has ordered a full investigation into the country's recent missile launch failures, South Korea's Yonhap news agency reported Friday. Two tests of the indigenous-built Musudan intermediate-range ballistic missiles failed earlier this month.

The probe is aimed at finding a fault in the making of the missiles amid suspicion of sabotage by the U.S. and South Korea. The North's State Security Minister Kim Won Hong is heading the special team put together for the probe which has 60 members, a North Korean defector and executive director of Seoul-based dissidents' group, North Korea Intellectuals Solidarity, said at a press conference.

"Kim has instructed the special investigation team to implement a probe into the national defense sector starting on November 1 to make the causes for the launch failures clear," Kim Heung-kwang said. "Officials and workers who engaged in the launches of the missiles are now banned from travelling and their mobiles phones are confiscated to check their conversation records."

Kim Jong Un reportedly believes that the Musudan missile failures may be linked to spies from the U.S. and South Korea who may have meddled with parts imported from foreign countries.

Test firing of Musudan missiles have been conducted eight times since April 15, reports said, but only one launch was successful.

North Korea has been making progress in the development of its nuclear and long-range weapons capability despite increasing pressure from the West and rival South Korea. The United Nations strongly condemned the recent attempts at test-firing ballistic missiles that were conducted after the reclusive country's fifth nuclear test.