According to South Korea’s military, North Korea has fired two short-range ballistic missiles into the sea.
South Korea said the missiles, launched off the east coast, flew some 300 miles and fell into the water.
Shortly after the launch, Pyongyang announced it “nullifies” all inter-Korean cooperative projects and will liquidate South Korean assets in the country.
Most South Korean assets in North Korea are in the jointly-operated Kaesong industrial zone.
South Korea pulled out of the Kaesong complex in February, after North Korea’s latest long-range missile launch of a satellite. At the time, the North called the shutdown “a declaration of war” and designated Kaesong as a military zone.
On March 9, North Korea’s leader Kim Jong-un also claimed scientists have developed nuclear warheads small enough to fit on ballistic missiles.
However, South Korea’s defense ministry said it thought North Korea had “not yet secured miniaturized nuclear warheads”.
The claim is critical, as without miniaturization Pyongyang cannot put its nuclear weapons on missiles – an ability many analysts think could still be several years away.
In response to the miniaturization claims, State Department spokesman John Kirby said of Kim Jong-un that “the young man needs to pay more attention to the North Korean people and taking care of them, than in pursuing these sorts of reckless capabilities”.
The two missiles launched on March 10 were fired from Hwanghae Province, the South Korean military said. It added that the missiles later fell into the sea off North Korea’s east coast, without providing further details.
Japan promptly lodged a protest to North Korea via its embassy in Beijing, over the latest launches, reported Kyodo news agency.
The missile launches are seen as North Korea’s response to the UN imposing some of its strictest sanctions, after the North conducted its fourth nuclear test in January and last month launched a satellite, both in contravention of existing sanctions.
Tensions have been especially high this week as US and South Korean forces hold their annual joint military exercises known as Key Resolve and Foal Eagle.
This year they are the largest ever, with about 17,000 US personnel and around 300,000 South Korean troops participating – both significant increases on 2015, in addition to increased naval and air force assets.