North Korea has conducted mass evacuation drills in towns across the country as ‘preparation for war,’ it was reported on Saturday.
Sources in the isolated Communist country reported that the rare drills were being conducted in ‘secondary and tertiary cities and towns’ over the course of the last week.
There were no reported drills in the capital, Pyongyang.
News of the drills, which included so-called ‘blackout’ exercises whereby whole towns would turn out all the lights at night time so as to avoid illuminating enemy targets, was first reported by NK News.
‘I have never heard of this type of training exercises before in North Korea, but am not surprised,’ Chun In-bum, a former South Korean military officer, said.
‘They must realize how serious the situation is.’
NK News quoted an anonymous source as saying that the last time drills which approached this scale were conducted was in 2003, when North Korea carried out air raid exercises.
‘I have never heard of evacuation exercises happening before,’ one source told NK News.
News of the reported drills came in light of heightened diplomatic tensions between North Korea and the West.
Earlier on Saturday, US Defense Secretary Jim Mattis issued a warning to North Korea that the country is no match for a decades-old American-South Korean alliance.
'Make no mistake - any attack on the United States or our allies will be defeated, and any use of nuclear weapons by the North will be met with a massive military response that is effective and overwhelming,' he said during a news conference in Seoul on Saturday.
With South Korean Defense Minister Song Young-moo at his side, Mattis accused the North and Supreme Leader Kim Jong-un of illegal and unnecessary missile and nuclear programs - and said the threat of a nuclear missile attack by North Korea is accelerating.
Mattis said North Korea engages in 'outlaw' behavior and that the US will never accept a nuclear North.
'North Korea has accelerated the threat that it poses to its neighbors and the world through its illegal and unnecessary missile and nuclear weapons programs,' he said, adding that US-South Korean military and diplomatic collaboration thus has taken on 'a new urgency'.
'I cannot imagine a condition under which the United States would accept North Korea as a nuclear power,' he said.
As he emphasized throughout his week-long Asia trip, which included stops in Thailand and the Philippines, Mattis said diplomacy remains the preferred way to deal with the North.
Mattis' comments did not go beyond his recent statements of concern about North Korea, although he appeared to inject a stronger note about the urgency of resolving the crisis.
While he accused the North of 'outlaw' behavior, he did not mention that President Donald Trump has ratcheted up his own rhetoric.
In August, Trump warned the North not to make any more threats against the US and said that, if it did, it would be met with 'fire and fury like the world has never seen.'
The North says it needs nuclear weapons to counter what it believes is a US effort to strangle its economy and overthrow the Kim government.
South Korea's conservative politicians have also called for the US to bring back tactical nuclear weapons that were withdrawn from the Korean Peninsula in the 1990s, which they say would make clearer the US intent to use nukes in a crisis.
But Mattis and Song were strongly dismissive of the idea.
'When considering national interest, it's much better not to deploy them,' said Song, adding that the allies would have 'sufficient means' to respond to a North Korean nuclear attack even without placing tactical nukes in the South.
Trump entered office declaring his commitment to solving the North Korea problem, asserting that he would succeed where his predecessors had failed.
His administration has sought to increase pressure on Pyongyang through UN Security Council sanctions and other diplomatic efforts, but the North hasn't budged from its goal of building a full-fledged nuclear arsenal, including missiles capable of striking the US mainland.