North Korea has "appeared to launch a ballistic missile towards Japan" with ships warned not to approach, officials say.
The suspected missile launch is the sixth in 12 days, marking the first since it fired an intermediate-range missile over Japan yesterday as tensions continue to rise.
In a tweet, Japan's Ministry of Defence said: "A possible ballistic missile was launched from North Korea.
"We will let you know as soon as we have further news."
There are reports of air raid sirens blaring across Japan as a result of the news.
The official Twitter account of Japan's Prime Minister, Fumio Kishida, added: "A projectile that appears to be a North Korean ballistic missile has likely flown over Japan."
This comment was shortly amended, with the portion of the statement saying a missile has "likely flown over Japan" removed.
Vessels have reportedly been told that they should not approach any falling objects and report relevant information to the Japan Coast Guard.
South Korea’s Joint Chiefs of Staff said the launch was made on Thursday morning but issued no further details, although it's reported that two possible ballistic missiles landed outside Japan's exclusive economic zone.
In response to the launch, Japan's Prime Minister issued a number of instructions to the public.
He said: "1. Dedicate maximum effort to gather and analyze information, and provide the public speedy and adequate information.
"2. Ensure the safety of aircraft, vessels, and other assets.
"3. Take all possible measures for precaution, including readiness for contingencies."
The launch came two days after North Korea fired an intermediate-range missile over Japan for the first time in five years in an apparent response to US military drills with South Korea and Japan.
It follows reports made earlier today that a malfunctioning South Korean ballistic missile blew up during a live-fire drill with the US - a reprisal for North Korea’s successful launch a day earlier of a weapon that flew over Japan.
The missile fired by Pyongyang yesterday had the range to strike the US territory of Guam.
The explosion and subsequent fire from the South Korean missile today panicked and confused residents of the coastal city of Gangneung, who were already uneasy over the increasingly provocative weapons tests by rival North Korea.
Their concern that it could be a North Korean attack only grew as the military and government officials provided no explanation about the explosion for hours.
And it appears North Korea has struck again tonight.
In relation to the botched attempt by South Korea earlier, its Joint Chiefs of Staff said no injuries have been reported from the explosion, which involved a short-range Hyumoo-2 missile that crashed inside an air force base in the outskirts of the city. It said the crash did not affect any civilian facilities.
During the same drill, the US military launched four of its own missiles that are part of the Army Tactical Missile System and South Korea fired another Hyumoo-2 successfully.
The US and South Korean militaries are conducting the joint exercises to show their ability to deter a North Korean attack on the South. In addition to missile launches, they involved bombing runs by F-15 strike jets using precision munitions.
North Korea’s successful launch of a nuclear-capable ballistic missile hours before the drills was the country’s most provocative weapons demonstration since 2017 and was its fifth round of weapons tests in 10 days.
That missile has a range capable of striking Guam, which is home to one of the largest military facilities maintained by the US in Asia. North Korea in 2017 also tested missiles capable of hitting the continental United States.
