North Korea launches ballistic missile towards Sea of Japan

North Korea has launched a ballistic missile towards the Sea of Japan, the Republic of Korea's Joint Chiefs of Staff said.

"North Korea has launched a ballistic missile towards the Sea of Japan," the military said.

The DPRK earlier said it had tested a new underwater unmanned strike-type system on March 21-23. According to a DPRK state media report, it is a "secret weapon" - the Heil (Tsunami) nuclear unmanned underwater vehicle, which has been under development since 2012.

Also on 22 March Pyongyang tested four strategic cruise missiles, the Hwasal-1 (Arrow-1) and Hwasal-2, equipped with nuclear simulated warheads.

The DPRK's military tests are believed to be a response to joint exercises by the Republic of Korea and the US.