North Korea has fired a missile that passed over northern Japan, the Japanese government says.
The government's J-Alert warning system advised people in the area to take precautions early on Tuesday, but public broadcaster NHK said there was no sign of damage.
The Japanese military did not attempt to shoot down the missile, which passed over Japanese territory around 6:06am local time.
It's understood the missile was sent over the island just south of Hokkaido, and broke into three pieces in the water.
South Korean military officials say the missile flew a total of 2700km, at a height of 550km.
Locals in the area have been told to take precautions including finding shelter in solid buildings.
Local man Joe @jtnarsisko says he woke up with a siren and an announcement over town loudspeakers.
It's the 13th missile launched by North Korea this year according to Japanese news network NHK.
The Japanese Government's held emergency meetings on the development.
Prime Minister Shinzo Abe says "We will make utmost efforts to firmly protect the lives of the people", while Japanese Chief Cabinet Secretary Yoshihide Suga says the missile launch posed a "grave, unprecedented threat".
"What is significant about this, is not just the missile launch itself but the fact that most experts are pretty much persuaded North Korea can miniaturise nuclear warheads to fit onto it's missile force," said Griffith University's International Relations expert Professor Andrew O'Neil.
"This is highly provocative from a Japanese point of view because it's a message from Pyongyang, no matter what you say, no matter how you close you are to the US, we can strike you at any time without notice, with a nuclear device."
"I think this really just underscore just how vulnerable America's allies are to North Korea's nuclear capabilities."
So is it time for Australia to start worrying?
"Should Australians be adjusting their travel plans to North-East Asia, Japan and South Korea? I think at this stage, probably not."
"But I think everyone needs to keep a close watch on how the situation evolves. My sense is that North Korea may follow up with another test, but they usually know where to draw the line and I'd be surprised if it follows up with another over-flight of Japan with a missile."
Just weeks ago, US President Donald Trump issued a provocative threat to North Korea that he'd unleash "fire and fury" on the country if they didn't get their act together.
But Professor O'Neil isn't expecting any military retaliation from the US.
"I'm pretty sure the North Koreans are potentially expecting some fiery rhetoric from Washington, a few tweets the President, but in material terms probably not a lot will happen."
"What you may have is a request from the Japanese government for a demonstration of US commitment, the deployment of a few more assets into Japan, just to reassure the population the US remains committed. Frankly, North Korea is reading the US pretty well at the moment and know that the Americans aren't going to respond in any material way to this."