SEOUL, May 26 (UPI) — North Korea fired close-range ballistic missiles and other projectiles into the Yellow Sea on Tuesday, Seoul’s military said, in Pyongyang’s latest show of force as tensions remain high on the Korean Peninsula.

The projectiles were launched from the vicinity of Chongju, a city on North Korea’s west coast, at around 1 p.m., South Korea’s Joint Chiefs of Staff said in a text message to reporters.

“The detected North Korean missiles flew approximately 80 kilometers [50 miles], and South Korea and the U.S. are currently conducting a precise analysis regarding their exact specifications,” the JCS said.

South Korean and U.S. intelligence authorities tracked and shared information on the launches from their initial stages, while Seoul also exchanged information related to the ballistic missiles with Japan, the military added.

“Under a robust South Korea-U.S. combined defense posture, the military is closely monitoring North Korea’s various movements and maintaining the capability and readiness to overwhelmingly respond to any provocation,” the JCS said.

The launches were the North’s first known missile tests since April, when Pyongyang conducted a series of weapons drills that included ballistic missiles carrying cluster bomb warheads.

The tests come as North Korea hardens its military posture toward Seoul and formally abandons decades-old reunification language.

Pyongyang recently revised its constitution to remove references to reunification with South Korea, cementing leader Kim Jong Un’s push to redefine inter-Korean ties as relations between two separate states.

The two Koreas remain technically at war because the 1950-53 Korean War ended in an armistice rather than a peace treaty.

Last week, Kim called for strengthening frontline defenses along the border with South Korea to create an “impregnable fortress.”

South Korean President Lee Jae Myung, who has sought to ease tensions since taking office in June, said Tuesday that Seoul must strengthen its military capabilities in response to North Korea’s growing nuclear and missile threats.

During a Cabinet meeting, Lee instructed officials to accelerate development of advanced weapons systems, including nuclear-powered submarines, while expanding the military’s use of artificial intelligence and drone technologies.