North Korea has reportedly conducted mass evacuation drills as it prepares for the possibility of war.
South Korea-based NK News said several sources had reported the drills were being conducted in "secondary and tertiary cities and towns" over the last week.
None were observed in the capital Pyongyang and most were carried out on the pariah state's east coast, which borders the Sea of Japan.
Blackout drills, where towns turn off all light sources at night to avoid illuminating targets for the enemy, were also conducted.
“I have never heard of this type of training exercises before in North Korea, but am not surprised,” former South Korean three-star lieutenant general LTG Chun In-bum told NK News. "They must realise how serious the situation is.
"In this day and age of precision bombing and all-weather capabilities, [such] North Korean civil exercises either come from ignorance of modern war or just a propaganda campaign to frighten their own people and induce obedience.”
One anonymous source said they had "never heard of evacuation exercises happening before."
Another said: “There used to be air raid drills in 2003, but not since then.
“A mass evacuation would be impossible not to notice.”
The threat North Korea launching a nuclear missile attack is accelerating, US Defence Secretary James Mattis has said.
General Mattis accused the North of illegal and unnecessary missile and nuclear programmes and pledged to repel any strike.
"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 had thus taken on "a new urgency."
"I cannot imagine a condition under which the United States would accept North Korea as a nuclear power," he added.
