seoul, south korea - North Korea has fired an unidentified ballistic missile over Japan, in an escalation not seen in years, prompting Tokyo to evacuate some residents in the northern prefectures of Hokkaido and Aomori on Tuesday morning.

Hirokazu Matsuno, Japan's chief Cabinet secretary, told reporters the missile was launched at 7:22 a.m., before splashing into the Pacific Ocean outside Japan's exclusive economic zone 22 minutes later.

South Korea's Joint Chiefs of Staff (JCS) called the projectile an intermediate-range ballistic missile (IRBM), launched from North Korea's northern Jagang area, flying a distance of 4,500 kilometers with a flight altitude of 970 kilometers.

A TV screen showing a news program reporting about North Korea's missile launch with file footage of North Korean leader Kim Jong Un, is seen at the Seoul Railway Station in Seoul, South Korea, Oct. 4, 2022.

Japanese Prime Minister Fumio Kishida, who marks his one-year anniversary as head of state on Tuesday, strongly condemned the missile launch, calling it an "outrageous" act.

Defense Minister Yasukazu Hamada later added the missile flew over Japan for about one minute, soaring further than previous intermediate-range missiles, estimated at 4,600 kilometers, before landing in waters some 3,200 kilometers east of Japan.

That the missile was shot over Japanese territory takes the escalatory mood in the region even higher, a decision Adrienne Watson, the U.S. National Security Council spokesperson, in a statement. described as "dangerous and reckless" and shows North Korea's "blatant disregard for United Nations Security Council resolutions and international safety norms" on Tuesday.

Testing

North Korea had last tested a Hwasong-12 IRBM in late January of this year, after which its state media explained its lofted trajectory as intentional, done "in consideration of the security of neighboring countries" - in apparent reference to Japan. That missile was estimated to have a range capable of putting Guam within reach.

The latest ballistic missile launch is likely to exceed that range. Some 3,400 kilometers separates Pyongyang and Guam, which houses a U.S. strategic naval base.

Hwasong-12 IRBMs were also tested in August and September of 2017, when Japan last issued a call to shelter after missiles flew over Hokkaido.

Tensions have been on the rise on the Korean peninsula in recent days, with Tuesday's launch upping the ante from the short-range ballistic missiles Pyongyang had fired on September 25, 28, 29 and October 1. The fifth test in 10 days follows a major joint naval exercise between the U.S. and South Korea featuring the nuclear-powered USS Ronald Reagan supercarrier, which resumed for the first time in five years.

A trilateral anti-submarine military exercise with Japan was also conducted for the first time since 2017 off South Korea's coast.

Possible return to nuclear testing

A return to nuclear testing also remains a strong possibility. South Korea's spy agency last week told lawmakers a seventh nuclear test, should it materialize, would most likely fall between October 16 - the first day of China's National Congress of the Communist Party - and November 8, the U.S. midterm elections.

At an Armed Forces Day ceremony on Saturday, South Korean President Yoon Suk Yeol warned North Korea against any nuclear provocations, saying a "resolute and overwhelming" response would be ready from the allies should it decide to use nuclear weapons.