North Korea fired a ballistic missile over Japan on Tuesday, its neighbors said, stepping up tests of weapons designed to strike key targets in US regional allies amid a stalemate in nuclear diplomacy.

The Japanese Prime Minister’s office said at least one missile had been fired from the country North Korea flew over Japan and is believed to have landed in the Pacific Ocean.

It said authorities issued a warning to residents in the northeastern regions to evacuate nearby buildings, reportedly the first such warning in five years.

Train services were temporarily suspended in the Japanese regions of Hokkaido and Aomori. They later resumed operations after the government reported that a North Korean missile appeared to have landed in the Pacific Ocean.

South Korea’s Joint Chiefs of Staff said it also detected the launch of a ballistic missile that was fired into North Korea’s eastern waters. It did not include any additional details, such as how far the weapon flew.

The launch is North Korea’s fifth round of weapons tests in the past 10 days, seen as an apparent response to military exercises between South Korea and the United States. North Korea views such drills as a rehearsal for an invasion.

The missiles fired during the last four launches were of short range and landed in the waters between the Korean Peninsula and Japan. These missiles are capable of hitting targets in South Korea.