North Korea has fired three anti-ship cruise missiles into the country’s eastern sea, South Korean military officials confirmed.

Pyongyang earlier announced it had test-fired a new submarine-launched weapon.

If its claims of an underwater launch are confirmed it would mark a step-change in the capability of the secretive nuclear-armed state’s military arsenal. The submarine platform would be much harder to detect than land-based ballistic missiles.

North Korean leader Kim Jong-un personally directed the test and called the missile a “world-level strategic weapon” and the launch an “eye-opening success”, the regime’s official Korean Central News Agency said. The report did not reveal the timing or location of the launch.

Kim declared North Korea now has a weapon capable of “striking and wiping out in any waters the hostile forces infringing upon the sovereignty and dignity of (North Korea)”.

The weapons fired were reportedly KN-01 missiles, which were also test-fired in February in an event personally attended by Kim.

An official from Seoul’s joint chiefs of staff said missiles were fired within a span of an hour in the early evening on Saturday from an area near the communist state’s eastern port city of Wonsan.

South Korean officials believe the regime is advancing its efforts to miniaturise nuclear warheads to mount on such missiles.

There had been expectations that Kim would attend Victory Day celebrations in Russia today in his first trip away from the country, but North Korea sent the head of its parliament instead.