Updated: 05/05/17 : 11:53:19Printable Version
US and South Korean agents are plotting to kill North Korean leader Kim Jong-un, state media report.
A statement by the ministry of state security said a terrorist group backed by the CIA and South Korea's intelligence agency had entered the country to attack with a bio-chemical substance.
It said North Korea would find and "mercilessly destroy" the terrorists.
It comes amid high tensions in the region.
The statement, carried by North Korean news agency KCNA
, said the alleged plot included the use of "biochemical substances including radioactive substance and nano poisonous substance".
The Supreme Leader would have been targeted at a military parade and public procession, with the results not be visible for six to 12 months afterwards, it said.
A recent war of words between the West and Pyongyang has escalated in recent weeks, with North Korea threatening to carry out a sixth nuclear test.