SEOUL/TOKYO: North Korea fired a second missile over Japan far out into the Pacific Ocean today, South Korean and Japanese officials said, deepening tension after Pyongyang’s recent test of its sixth and most powerful nuclear bomb.

The UN Security Council was to meet later in the day to discuss the launch at the request of the United States and Japan, diplomats said.

The missile flew over Hokkaido in the north and landed in the Pacific about 2,000 km (1,240 miles) to the east, Japanese Chief Cabinet Secretary Yoshihide Suga told reporters.

The missile reached an altitude of about 770 km (480 miles) and flew for about 19 minutes over about 3,700 km (2,300 miles), according to South Korea’s military - far enough to reach the U.S. Pacific territory of Guam, which the North has threatened before.

On Aug 29, North Korea launched an intermediate-range ballistic missile, the Hwasong-12, which traveled 2,700 km (1,700 miles) over Japan.

“The range of this test was significant since North Korea demonstrated that it could reach Guam with this missile,” the Union of Concerned Scientists said in a statement.

But it said the accuracy of the missile, still at an early stage of development, was low.

Warning announcements about the missile blared around 7 a.m. (2200 GMT Thursday) in parts of northern Japan, while many residents received alerts on their mobile phones or saw warnings on TV telling them to seek refuge.

US Secretary of Defense Jim Mattis said the launch “put millions of Japanese into duck and cover”, although residents of northern Japan appeared calm and went about their business as normal after the second such launch in less than a month.

The US military said soon after the launch it had detected a single intermediate range ballistic missile but the missile did not pose a threat to North America or Guam, which lies 3,400 km (2,110 miles) from North Korea.

US officials repeated Washington’s “ironclad” commitments to the defense of its allies. Secretary of State Rex Tillerson called for “new measures” against North Korea and said the “continued provocations only deepen North Korea’s diplomatic and economic isolation”.