North Korea said Friday it had tested a nuclear-capable underwater attack drone designed to launch a radioactive tsunami, as its leader Kim Jong Un vowed to make his rivals "plunge into despair."

Iran PressAsia: North Korea claimed Saturday it had tested another underwater nuclear attack drone, its latest response to joint US-South Korea military drills, though analysts have questioned whether Pyongyang has such a weapon.

In recent weeks, North Korea has tested what state media have described as an underwater nuclear-capable drone and also carried out the launch of an intercontinental ballistic missile.

"A national defence science research institute in the DPRK carried out a test of underwater strategic weapon system from April 4 to 7," the official Korean Central News Agency said.

The nuclear-capable drone called "Haeil" — meaning tsunami in Korean — can be deployed from the coast or towed by a ship in order to destroy naval strike groups or enemy ports, the state-run KCNA news agency reported.

On March 23, North Korea claimed it tested an underwater nuclear attack drone able to unleash a "radioactive tsunami", as it blamed US-South Korea exercises for a deteriorating regional security situation. 219