North Korea said it has tested a new nuclear-capable underwater attack drone which it claims could release a radioactive tsunami.
The North Korean state news agency KCNA reported that during the test, the new North Korean drone cruised underwater at a depth of 80-150 metres (260-500ft) for more than 59 hours and detonated a non-nuclear payload in waters off its east coast on Thursday.
Dubbed the 'Haeil', state media claims that this unmanned underwater vehicle is intended to make sneak attacks in enemy waters and destroy naval strike groups as well as major operational ports by creating a large radioactive wave through an underwater explosion.
North Korea's leader Kim Jong-Un was pictured in images released by KCNA personally testing and inspecting the Haeil.
It was reported that he personally guided tests of the weapon 29 times, with its operational deployment given the green light by the ruling party's top leadership.
Analysts believe that North Korea is showing off its increasingly diverse nuclear threats to Washington and Seoul, although they remain sceptical about whether the underwater vehicle is ready for deployment.
Reportedly under development since 2012, the North Korean state media also published images featuring an object moving underwater close to the surface and an explosion above the water.
North Korea last month fired a long-range ballistic missile after warning of a strong response to upcoming annual military drills by South Korea and the US.
According to Japan's government, the missile landed inside Japan's maritime borders.
North Korea's first missile firing since 1 January came after Pyongyang threatened that they would respond to the upcoming drills.