Seoul voices 'deep concern' over execution of North Korea leader's uncle

North Korean leader Kim Jong Un looks at his uncle, Jang Song Thaek (left), during a parade to commemorate the 60th anniversary of the signing of a truce in the 1950-1953 Korean War in this July 27, 2013 file photo. -- PHOTO: REUTERS
North Korean leader Kim Jong Un looks at his uncle, Jang Song Thaek (left), during a parade to commemorate the 60th anniversary of the signing of a truce in the 1950-1953 Korean War in this July 27, 2013 file photo. -- PHOTO: REUTERS

SEOUL (AFP) - South Korea expressed deep concern on Friday after North Korea announced the execution of leader Kim Jong Un's uncle.

In a stunning downfall, Jang Song Thaek - who had been seen as Kim's political regent and the country's unofficial No. 2 - was executed on Thursday immediately after a special military trial, the North's state media said.

"The government has deep concerns about a recent series of developments in North Korea and is watching the situation closely," the South's Unification Ministry said in a statement.