North Korea on Tuesday fired a ballistic missile over Japan, escalating tests of weapons designed to strike key targets in regional US allies amid stalled nuclear diplomacy.The Japanese prime minister's office said at least one missile fired from North Korea flew over Japan and was believed to have landed into the Pacific Ocean.It said authorities have issued an alert to residents in north-eastern regions to evacuate nearby buildings in what was reportedly the first such alert in five years.

North Korea on Tuesday fired a ballistic missile over Japan, escalating tests of weapons designed to strike key targets in regional US allies amid stalled nuclear diplomacy.The Japanese prime minister's office said at least one missile fired from North Korea flew over Japan and was believed to have landed into the Pacific Ocean.It said authorities have issued an alert to residents in north-eastern regions to evacuate nearby buildings in what was reportedly the first such alert in five years.