North Korea conducts test of underwater nuclear weapons system -KCNA

North Korea has conducted a test of its underwater nuclear weapons system in a protest against this week's joint military drills by South Korea, the United States and Japan, state media KCNA said on Friday.

The test of the "Haeil-5-23" system, a name North Korea has given to its nuclear-capable underwater attack drones, was carried out by the defence ministry's think tank in the waters off its east coast, the report said, without specifying a date. "Our army's underwater nuke-based countering posture is being further rounded off and its various maritime and underwater responsive actions will continue to deter the hostile military manoeuvres of the navies of the U.S. and its allies," an unnamed spokesman of the ministry said in a statement, according to KCNA.

The navies of South Korea, the United States and Japan staged this week three-day joint drills

until Wednesday, alongside the U.S. aircraft carrier Carl Vinson, as part of efforts to improve their responses to nuclear-armed North Korea's threats.