SEOUL — North Korea fired multiple short range ballistic missiles into waters east of the Korean peninsula Thursday, Seoul's military said, the nuclear-armed country's first major weapons test since early July. Leader Kim Jong Un's regime has staged dozens of launches this year, part of a testing spree that experts say could be linked to North Korea's alleged illicit supplying of weapons to ally Russia for use in Ukraine. Pyongyang has denied any sanctions-busting weapons trade with Russia, but with diplomacy long stalled, it declared South Korea its "principal enemy" this year and recently moved nuclear-capable weapons to border areas. Seoul's Joint Chief of Staff said it had detected multiple "short-range ballistic missiles" fired early Thursday morning from Pyongyang into the East Sea, or Sea of Japan. The missiles splashed down after flying around 360 kilometers (220 miles), the JCS said, adding it had "immediately detected, tracked, and monitored" the launch and was sharing information with allies Tokyo and Washington. It said the test was "a clear provocation that seriously threatens peace and stability on the Korean Peninsula." People watch a television screen showing a news broadcast with file footage of a North Korean missile test, at a train station in Seoul on September 12, 2024. AFP PHOTO Japan's defense ministry also confirmed the missile test, with Prime Minister Fumio Kishida saying the country had "already lodged a protest with North Korea." It is Pyongyang's first ballistic missile test since July 1, and comes days after the isolated country marked a key anniversary celebrating the founding of the ruling regime. North Korea has regularly launched missiles around September 9, its foundation day, including conducting its fifth nuclear test on the same day in 2016. A JCS spokesperson told reporters it was possible the Thursday ballistic missile launch could mean the North "tested it for export to Russia." North Korea has recently bolstered military ties with Moscow, with President Vladimir Putin making a rare visit to Pyongyang in June, where he signed a mutual defense agreement with Kim. Experts have long said North Korean missiles are being deployed in Ukraine, and a new Conflict Armament Research report this week employed debris analysis to show "that missiles produced this year in North Korea are being used in Ukraine."