North Korea fired three ballistic missiles into the sea off its east coast on Monday, South Korea's military said, as the leaders of the Group of 20 major economies held a summit in China, the North's main diplomatic ally.
The missiles were fired from a region south of the capital Pyongyang just after noon local time (0300 GMT) and flew about 1,000 km (600 miles), hitting Japan's air defense identification zone, the South's Office of the Joint Chiefs of Staff said.
"We are still analyzing details but this is a grave threat to our nation's security, and we express deep concern," the Japan Defence Ministry said in a statement.
