South Korea’s Ministry of Defense has detected three launches of short-range guided missiles by North Korea, it said.
Japan confirmed the report of the launches, saying its military had detected them too.
The Korean Peninsula is emerging from the latest period of high tension, which started after the North conducted its third nuclear test in February. The test was met with condemnation and a new round of sanctions by the UN Security Council.
South Korea and the US conducted massive war drills shortly after the test, with the US sending some of its most powerful military hardware in a demonstration of strength. Pyongyang called the buildup a provocation and threatened to use its nuclear arsenal, if attacked. The North says the aggressive stance of Washington and Seoul justifies its development of nuclear weapons.