South Korea’s military fired warning shots at a North Korean patrol vessel on Saturday, just days after North Korea tested a new Hwasong-18 missile that triggered alarm in northern Japan. The incident occurred around 11 am local time when the North Korean boat, chasing a Chinese fishing boat, temporarily crossed the disputed western sea boundary near South Korea’s Baekryeong Island. The boundary was established by the UN following the Korean War in 1953.

As a South Korean high-speed vessel responded to the North Korean patrol vessel’s intrusion, poor visibility led to a collision with the Chinese fishing boat. Some South Korean troops suffered minor injuries as a result. South Korea’s joint chiefs of staff downplayed the collision, stating that the military would remain on alert for any “potential provocations” by North Korea.

South Korea has been conducting major joint military drills with the United States, the largest in recent years, to deter North Korea from further provocative weapons testing. Another exercise, involving around 110 warplanes, will begin on Monday and last until April 28th.

North Korea claims that its Hwasong-18 missile, an intercontinental ballistic missile capable of targeting mainland America, will “radically promote” the nation’s nuclear counterattack capabilities. Kim Jong Un is reported to have “guided” this week’s missile test. North Korea has launched over 100 missiles into the sea since the beginning of 2022, but claims that the latest test did not pose a threat to neighboring countries.

Concerns have arisen as North Korea has not responded to South Korea’s calls on cross-border hotlines, intended to prevent accidental incidents like Saturday’s, for over a week. North Korea does not recognize the poorly marked UN-established border and contends that it should be positioned further south. Past clashes at sea include a 2010 incident in which South Korea accused North Korea of attacking a warship, resulting in the deaths of 46 soldiers.