A submarine fired weapons into the sea off the eastern North Korean coastal city of Sinpo on Sunday morning, according to the state-run KCNA news agency.
The South Korean army, quoted by the Yonhap agency, confirmed for its part that it detected a missile launch, without giving further details, according to the Yonhap news agency.
KCNA said the launch was successful and the missiles hit their designated targets near the east coast of the Korean Peninsula.
Photos and videos released by the North Korean state media showed the “8.24 Yongung” submarine and a missile flying into the sky from the sea, followed by a trail of smoke and fire.
But analysts expressed doubts about the progress of North Korea’s submarine program.
Park Won-gon, a professor at Seoul’s Ewha University, considered that state media images suggest the missile was fired from the surface of the water and not with the ship submerged.
“So there is no point in shooting from a submarine because there is no stealth,” Park told AFP.
North Korea had warned that the military exercises by Washington and Seoul would be seen as a “declaration of war.”
The two allied countries began their biggest joint exercises in five years on Monday.
According to KCNA, the launch “shows the invariable” determination of North Korea to face a situation in which forces “of US imperialism and its puppet South Korea show more and more clearly that they are maneuvers” against Pyongyang.
He added that the launch made it possible to “verify the current operational posture of the nuclear deterrence means in different spaces.”
royal war
In a separate statement, the North Korean Foreign Ministry said the United States is “plotting” to convene the UN Security Council to discuss human rights in the communist country, coinciding with the moves.
North Korea “bitterly denounces America’s vile ‘human rights’ racket as the most intense expression of its hostile policy” toward Pyongyang.
Washington and Seoul have intensified their military cooperation in the face of growing military and nuclear threats from the North, which has increased its weapons tests in recent months.
Monday’s exercises, called Freedom Shield, should last 10 days and will focus on the “changing security environment” due to North Korean aggressiveness, according to the two allies.
The South Korean military revealed this month that it, along with US special forces, was conducting military exercises that included simulating precision strikes against key North Korean installations, ahead of Freedom Shield.
The exercises infuriate Pyongyang, which sees them as exercises for an invasion, while pointing out that its nuclear and ballistics programs are self-defense.
“Pyongyang has developing military capabilities and wants to test them, and likes to use the cooperation between Washington and Seoul as an excuse,” said Leif-Eric Easley, a professor at Ewha University.
Last year, North Korea declared it an “irreversible” nuclear power and launched a record number of missiles.
Last week, leader Kim Jong Un ordered his military to step up its exercises in preparation for a “real war.”