Updated

North Korea’s nuclear program has put the world on high alert, and it is driving more and more Americans to go underground.

The Pentagon confirmed that Thursday night the Kim Jong Un regime fired an Intercontinental Ballistic Missile that appears to have landed in the waters within a couple hundred miles of Japan’s coast.

As North Korea conducts more frequent missile tests nervous people in the U.S. and elsewhere are doing something about it, purchasing underground bomb shelters to protect themselves.

Recent reports show that citizens of Japan have been rushing to buy bomb shelters after North Korea tested another intercontinental ballistic missile three weeks ago. Japan hasn’t gotten along with the hermit kingdom for decades and is well within range of an attack -- Tokyo is just 800 miles away -- yet something about these new threats seems to have people there more on edge.

“We offer both simple and luxurious bunkers, but rest assured that they all offer the same level of protection.”

— Gary Lynch, Rising S Bunkers

Indeed, a Japanese company, Earth Shift, that builds shelters to protect families from natural disasters told Fox News that most of their clients now are people concerned about an attack.

“The amount of inquiry that we receive in a month has been increased,” the company said in an email. “It was about one to five times in a month, but after North Korea evolution [was] picked up [by the] media, we receive around 50 times in a month.”

Kim Jong Un

Kim's hostilitiy has put the world on edge

One American underground shelter manufacturer located in Texas, Rising S Company, has “seen an astronomical uptick in our sales for Japan,” according to General Manager, Gary Lynch.  “In the past two weeks, nearly 90% of our calls are from this region and all have the same concern,” he told Fox News.  That concern, he says, is North Korea.

Rising S builds shelters that range in size--from a 96-square-foot abode for two to the massive 'Aristocrat' which can sleep 44 people, includes 10 individual master bedrooms and is priced at over $8 million. Lynch said in Japan, where space is tight, the more popular shelters are the smaller ones.

The company’s bunkers are designed to last forever and are able to hold a year's worth of food per resident.  Lynch said Rising S tries to make their shelters feel more like a home. “If people are more comfortable inside their shelter, then they are more likely to use it and not have a problem waiting out the dangerous elements that could loom outside,” he said.

"Built in America, installed worldwide," Lynch said. “We offer both simple and luxurious bunkers, but rest assured that they all offer the same level of protection.”  He said that he sells in many countries where people fear their neighboring countries and even their own governments, like Venezuela.

Right now, though it is all about North Korea.

“North Korea has been a threat for quite some time now, but our previous administration chose to ignore the warning signs and pretend they did not exist,” Lynch told Fox News. “Now that Trump has taken office we are seeing this threat being addressed and it is causing tensions not only in that region but for the U.S. mainland as well.”

Just this week a leading North Korea expert told Fox News that Pyongyang is a year and a half away from creating a nuclear missile capable of reaching the United States.

That concerns Lynch’s clientele in this country. “All of our recent calls from the west coast are showing this as their biggest concern,” he said.

A Rising S client from the San Francisco Bay area, who asked to remain anonymous, said she considered purchasing a bomb shelter for a long time.

But today, she said, “there is a sense of urgency now because of what is going on in the world today.”

Asked about North Korea, she said she believe the tensions in the region surrounding North Korea are at the highest levels since the Korean War.

“Although they have acted out in the past they did not have ICBMs capable of hitting the United States,” she said. “Being a resident of the San Francisco Bay area, we could potentially be a target.”

She said she knows others just as concerned as she is about North Korea.

“There are a few who thought I was crazy three months ago when I purchased my bomb shelter from Rising S Company, but those same people are now either purchasing one or have plans to do so,” she said.

Another Rising S client from Northern California who asked not to be identified told Fox News she purchased shelter just recently.

“I love it,” she told Fox News. “I feel so much safer.”

She said she wanted a shelter for a number of reasons and North Korea was one of them.

“North Korea could really f*** us up,” she said.

As Hawaii confronts the threat from North Korea, the state’s Emergency Management Agency says it is prepared.

“Preparedness = An informed public (including visitors) that know what to expect and what to do …… for all hazards,” agency head Vern Miyagi told Fox News in an email.

He attached a document to the email showing that his agency is taking steps to be prepared, including updating the siren warning system.

“In conjunction with the Defense Threat Reduction Agency and other state and federal agencies, prepare a planning scenario focused on a 15-kiloton nuclear weapon detonated 1,000 feet above the city of Honolulu,” the document says.

Miyagi attached another agency document that advises citizens what to do in the event of an attack.

“If you are indoors, stay indoors well away from windows,” it says. “If you are outdoors, seek immediate shelter in a building preferably a concrete structure.”

The advisory also recommends remaining “sheltered until you are told it is safe to leave or two weeks (14 days) have passed, whichever comes first.”

Two weeks after a nuclear blast in a concrete structure above ground, or in a bomb shelter underground, is advice that everyone we spoke with said hopefully will never need to be taken.

Additional Reporting: Kristine Kotta & Rebecca Kesten