North Korea fired two short-range ballistic missiles toward its eastern waters on Sunday, the latest in its barrage of weapons tests in recent days, after the North warned against the US redeployment of an aircraft carrier for a new round of drills with South Korean warships.
South Korea's Joint Chiefs of Staff said in a statement it detected the two missiles launched between 1:48 am and 1:58 am on Sunday from the North's eastern coastal city of Munchon.
It said South Korea's military has boosted its surveillance posture and maintains a readiness in close coordination with the United States.
The Japanese government also said North Korea fired what was possible ballistic missiles.
Japanese Prime Minister Fumio Kishida instructed officials to do their utmost to gather and analyze information about the suspected launches and inform the public of any accurate information quickly, while ensuring the safety of aircraft and ships around Japan and preparing for any contingencies, according to his office.
The Japanese coast guard said it has warned ships around the country's coasts about falling objects and urged them to stay away.
The launch, the North's seventh round of weapons tests in two weeks, came hours after the United States and South Korea wrapped a new round of naval drills off the Korean Peninsula's east coast.
The drills involved the nuclear-powered aircraft carrier USS Ronald Reagan and its battle group, which returned to the area after North Korea fired a powerful missile over Japan last week to protest the carrier group's previous training with South Korea.