A report filmed by the BBC saw adults and children sprinting indoors or sheltering behind walls as sirens wailed. Photo/BBC News
Japan has held its first air-raid drills since World War Two amid fears of a nuclear strike by North Korea.
People on the country's north-west coast practiced running for cover following Kim Jong-un's latest ballistic missile tests.
A report filmed by the BBC saw adults and children sprinting indoors or sheltering behind walls as sirens wailed, according to Daily Mail.
A voice over a loudspeaker could be heard saying: "A missile has been launched and is heading in this direction. Take cover in a concrete building."
It comes as North Korea has lashed out at the latest round of UN sanctions calling them "a rampant violation of our sovereignty and a frontal challenge to our republic."
Jong-un will take revenge "thousand-fold" on the US and unleash "decisive justice" on the US, the statement said, vowing "will never step back from strengthening our nuclear might."
The dictator will also never negotiate over nukes "as long as the anti-DPRK administration of the United States and its nuclear threat continue", it said.
The hermit-state issued the statement on Monday in response to the latest round of UN sanctions, which imposed a $1billion trade embargo on North Korean exports.
It also comes after Secretary of State Rex Tillerson suggested the US would be open to talks with Kim provided he halted his missile program.
The statement laid the blame for the latest round of sanctions squarely at the door of the United States, despite the fact that the UN resolution was jointly drafted with China - the North's closest trading partner and reluctant ally.
Fresh sanctions are "a product of the atrocities of the United States", it said, accusing the Trump administration of "making extreme anti-hostility policies and nuclear threats."
It called the latest test of the Hwasong-14 intercontinental ballistic missile "a stern warning" to the US, saying it is time America learns to "coexist with us".
Instead, America is "becoming more and more pernicious, and it is trying to drag the situation of the Korean peninsula back to nuclear battles."
By imposing sanctions America will only "hasten self-destruction", the statement says, adding that North Korea will "will not hesitate to use to any last resort."
However, the statement, which was published by state news agency KCNA, insisted that its mission to develop nuclear missiles is only designed as a defensive measure.
The statement came after a meeting between Chinese Foreign Minister Wang Yi and his North Korea counterpart Ri Yong Ho over the sanctions.
China urged North Korea to stop conducting missile and nuclear tests because it provokes the "international community's goodwill".
The United Nations Security Council at the weekend passed a new set of sanctions against Pyongyang over its weapons programmes, including bans on the export of coal, iron and iron ore, lead and lead ore as well as fish and seafood from the impoverished state.
The measures were approved unanimously - including by China, the North's sole major ally and economic lifeline, and Russia.
Kim Jong-un has long held the ambition to develop a nuclear weapon capable of ranging the mainland United States, and the most recent ICBM test shows he now has a missile capable of doing so.
However, it is not clear whether the North has yet developed a nuclear warhead small enough to be mounted to the missile.
It is also unclear whether the country has the technology to bring the warhead down successfully without it disintegrating.
But many weapons-control experts now believe the North will develop these capabilities some time in the next few years, a move that President Trump has warned "will not happen."
That ultimatum has raised the prospect of fresh conflict on the Korean Peninsula, if the US decides to stop Kim's nuclear program by force.