North Korea fired at least half a dozen missiles into the sea Thursday, including a long-range intercontinental ballistic missile that triggered evacuation warnings and halted trains in Japan as tensions in the region escalated.

The ICBM test was followed by launches of two short-range ballistic missiles, drawing swift condemnation from North Korea’s neighbors and the US, which reacted by extending joint air force drills with South Korea that have enraged Pyongyang.

South Korea’s military said North Korea later fired three more short-range missiles into waters off its eastern coast. Those launches came an hour after a senior North Korean military official issued a statement threatening retaliation over the extension of the US-South Korea drills.

South Korea’s Joint Chiefs of Staff said it detected that North Korea had fired an ICBM from an area near its capital at about 7:40 a.m. local time, followed by two short-range missiles an hour later from the nearby city of Kaechon.

The longer-range missile appeared to be fired at a high angle — possibly to avoid entering foreign territory — reaching a maximum altitude of 1,193 miles and traveling around 472 miles, according to South Korea’s military.

It wasn’t immediately clear whether the launch was successful.

Japan’s military announced similar flight details. It also said it lost track of one of the North Korean weapons, apparently the ICBM, after it “disappeared” above the waters between the Korean Peninsula and Japan.

The Japanese government initially feared North Korea had fired a missile over its northern territory but later adjusted its assessment. Japanese Chief Cabinet Secretary Hirokazu Matsuno said the alerts were based on a trajectory analysis that indicated a flyover.

The office of Japanese Prime Minister Fumio Kishida broadcast so-called “J-Alert” warnings through television, radio, mobile phones and public loudspeakers to residents of the northern prefectures of Miyagi, Yamagata and Niigata, instructing them to go inside strong buildings or underground.

There have been no reports of damage or injuries in the regions where the alerts were issued.

Bullet train services in some areas were temporarily suspended following the missile alert before resuming.

North Korean missile activity is a particular concern in Niigata, which is home to seven reactors at the Kashiwazaki-Kariwa nuclear power plant.

Those reactors are currently offline and Japanese authorities say no abnormalities have been detected.

On Sado island, just off Niigata’s northern coast, fishermen rushed back to land at the sound of sirens blaring from community speaker systems. One fisherman told NTV television he no longer feels safe going out to sea.

“We really have to be careful,” he said.

North Korea last flew a missile over Japan in October in what it described as a test of a new intermediate-range ballistic missile, which experts say would potentially would be capable of reaching Guam, a major US military hub in the Pacific.

The missile launches are the latest in a series of North Korean weapons tests in recent months that have raised tensions.

On Wednesday, North Korea fired a daily record of 23 missiles, drawing condemnation from Washington, Seoul and Tokyo.

Experts say North Korea is escalating brinkmanship aimed at forcing the United States to accept it as a nuclear power and negotiate economic and security concessions.

The US said in response to the launches that it’s willing to take “all necessary measures” to ensure the safety of the American homeland and allies South Korea and Japan.

The Biden administration also warned of unspecified “additional costs and consequences” if North Korea goes on to detonate a nuclear test device for the first time since September 2017.

Japanese PM Kishida blasted North Korea’s latest launches and said officials were analyzing the details of the weapons.

The office of South Korean President Yoon Suk Yeol said his national security director, Kim Sung-han, discussed the launches during an emergency security meeting at which members talked about plans to strengthen the country’s defense in conjunction with the US.

The office said South Korea will continue combined military exercises with the US in response to North Korea’s intensified testing activity, which it said would only deepen the North’s international isolation and unleash further economic shock to its people.

Adrienne Watson, a spokesperson for the US National Security Council, issued a statement saying the United States “strongly condemns” North Korea’s ICBM test.

“This launch, in addition to the launch of multiple other ballistic missiles this week, is a flagrant violation of multiple UN Security Council resolutions and needlessly raises tensions and risks destabilizing the security situation in the region,” Watson said.

She said the United States will take “all necessary measures” to ensure the security of America and its allies South Korea and Japan.

One of the more than 20 missiles North Korea shot on Wednesday flew in the direction of a populated South Korean island and landed near the rivals’ tense sea border, triggering air raid sirens and forcing residents on Ulleung island to evacuate. South Korea quickly responded by launching its own missiles in the same border area.

Those launches came hours after North Korea threatened to use nuclear weapons to get the US and South Korea to “pay the most horrible price in history” in protest of ongoing South Korean-US military drills that it views as a rehearsal for a potential invasion.

Following North Korea’s additional launches Thursday, the South Korean and US air forces agreed to extend their ongoing combined aerial drills past Friday to step up their defense posture in the face of North Korea’s increased weapons testing and growing nuclear threat.

The exercises include hundreds of South Korean and US warplanes staging around-the-clock simulated missions.

In a statement issued through state media, senior North Korean military official Pak Jong Chon accused the allies of pushing tensions to an “uncontrollable state” by extending their “provocative military acts.”

“The US and South Korea will get to know what an irrevocable and awful mistake they made,” he said.

US and South Korean officials say North Korea may up the ante in the coming weeks with a nuclear test, which would be its seventh overall.

“Should it go forward with a seventh nuclear test there would be additional costs and consequences,” State Department spokesperson Ned Price said Tuesday, adding that the test would be a “dangerous, reckless, destabilizing act.”

With Post wires