North Korea fired a barrage of ballistic missiles toward the sea off its east coast on Monday, a show of force that officials in Seoul and Tokyo linked directly to South Korea's first public test of a hypersonic missile days earlier — and to a bitter, weeks-long dispute over land mines that wounded South Korean soldiers at the border.

South Korea's Joint Chiefs of Staff said the missiles were launched from near Pyongyang at about 9:20 a.m. local time and flew more than 900 kilometers before splashing down. Japan's Defense Ministry separately tracked at least two missiles, estimating one traveled roughly 220 kilometers and another about 910 kilometers, reaching altitudes near 70 kilometers, and said both came down outside Japan's exclusive economic zone. Tokyo's state minister of defense, Takashi Koyari, said the weapons may have flown "irregular trajectories," and that Japan, the United States and South Korea were jointly scrutinizing the flight data, according to The Nation Thailand. A South Korean military official said the launch was most likely Pyongyang's answer to Seoul's own hypersonic missile test, overseen personally by President Lee Jae Myung on Oct. 8, per Reuters.

A Border Already on Edge

The launch landed on top of a far uglier dispute. On Sept. 21, two land mines exploded in the Demilitarized Zone, wounding three South Korean soldiers — two seriously, with one reportedly losing a foot. A joint South Korean–United Nations Command investigation concluded the mines had been planted by North Korean forces roughly a year earlier, a violation, the UNC said, of the 1953 armistice, according to Al Jazeera. Seoul demanded an apology and floated unspecified retaliatory steps; Pyongyang flatly refused.

Kim Yo Jong, sister of North Korean leader Kim Jong Un, dismissed Seoul's accusation as a "groundless" "farce" and branded the apology demand itself "despicable."

She went further days later, rejecting a South Korean offer of border talks as a "wild dream," and this week's missile launches followed an earlier North Korean test on Oct. 3 — a strike of more than 700 kilometers from Wonsan that Pyongyang described as a test of an "intermediate-range strategic missile." North Korea has now tested missiles more than ten times this year, Reuters reported.

Seoul's presidential office condemned Monday's launches as breaches of United Nations Security Council resolutions that "do not support stability on the Korean Peninsula." Japan's Koyari said the repeated tests "threaten the peace and safety of Japan, the region and the international community." Pyongyang itself issued no public statement on the launches as of Monday.

Neither side has shown signs of backing down. South Korea's military said it had stepped up surveillance for further launches and was sharing intelligence in real time with Washington and Tokyo, while North Korea has given no indication it will drop its fortification work along the border or entertain Seoul's apology demand. With both Koreas now trading weapons tests roughly weekly, officials and analysts increasingly expect the standoff — and the missiles — to continue rather than cool off.