A show of force by United States bombers off the Korean peninsula at the weekend has prompted North Korea to belatedly move its aircraft to the east coast and bolster other defences there.
South Korea's spy agency, which revealed this, also told a parliamentary committee yesterday that the North's radars had failed to detect the US warplanes at the time.
On Monday, North Korean Foreign Minister Ri Yong Ho insisted on Pyongyang's right to take countermeasures, including shooting down US bombers "even when they are not inside the airspace border of our country".
Some analysts say the KN-06, a surface-to-air missile system developed by North Korea, has the capability to shoot down US bombers.
South Korea, China and Russia all called for restraint.
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