North Korea launches missile over Japan

Tokyo (CNN)A North Korean missile fired over Japan Tuesday was denounced by Japanese Prime Minister Shinzo Abe as a "most serious and grave" threat.

The missile was fired just before 6 a.m. in Japan. The launch set off warnings in the northern part of the country urging people to seek shelter.

The unidentified missile flew over Erimomisaki, on the northern island of Hokkaido, and broke into three pieces before falling into the Pacific Ocean, about 1,180 kilometers (733 miles) off the Japanese coast.

The missile was in flight for about 15 minutes, Chief Cabinet Secretary Yoshihide Suga said at an emergency press conference. "There is no immediate report of the fallen objects and no damage to the ships and aircraft," he added.

Tuesday's launch is the first time North Korea has successfully fired a ballistic missile over Japan. Various stages of launch vehicles have overflown Japan during Pyongang's attempts to launch satellites into space in 1998, 2009, 2012 and 2016.

This is the fourth missile North Korea has fired in four days -- Pyongyang tested three short-range ballistic missiles, one of which failed, from Kangwon province that landed in water off the Korean Peninsula.

Abe speaks to Trump

Soon after the launch, Abe called it a "unprecedented serious and grave threat to Japan" that "significantly undermines the peace and security of the region."

The Japanese leader said he spoke with US President Donald Trump for 40 minutes.

"Japan and the US completely agreed that an emergency meeting at the UN Security Council should be held immediately and increase the pressure towards North Korea."

Trump reiterated that the United States "stands with Japan 100%," Abe said.

While the missile flew over Japanese territory, one analyst said it wasn't necessarily intended as a threat to Japan.

"If they're going to launch to a distance they've got to go over somebody. It looks to me like a risk reduction measure, they want to reduce the populated areas they fly over just in case anything goes wrong," said Joshua Pollack, a senior research associate at the James Martin Center for Nonproliferation Studies.

South Korea response

South Korea responded by conducting a bombing drill at 9:30 a.m. local time to test its "capability to destroy the North Korean leadership" in cases of emergency, an official with the country's Defense Ministry told CNN.

Yoon Young-chan, the head of South Korea's Presidential Public Affairs Office, told reporters that four F-15K fighter jets dropped eight one-ton MK-84 bombs at a shooting range.

The operation was meant "to showcase a strong punishment capability against the North," he said.

"We are fully ready to counter any threat from North Korea and will make unwavering efforts to protect the lives of our people and the security of our nation," South Korean Foreign Ministry spokesman Cho June-hyuck said.

Alerts in Hokkaido

Analysts believe Tuesday's launch shows a new level of confidence from the North Koreans.

"It is a big deal that they overflew Japan, which they have carefully avoided doing for a number of years, even though it forced them to test missiles on highly lofted trajectories, and forced them to launch their satellites to the south, which is less efficient than launching to the east (due to the Earth's rotational motion)," said David Wright, co-director of the Global Security Program at the Union of Concerned Scientists.

Pyongyang's missile tests are banned under United Nations Security Council resolutions, but that hasn't stopped North Korean leader Kim Jong Un from attempting to rapidly develop his country's nuclear and missile programs.

This time, the missile was launched near the North Korean capital of Pyongyang, which is rare.

CNN's Will Ripley, who is on the ground in Pyongyang, said the news had not been broadcast to people inside North Korea as of 9:45 a.m. local time.

Minutes after the missile was launched, residents in northern Japan received a text message urging them to seek shelter in a strong structure or a basement.