North Korea has fired what appears to be a short-range ballistic missile, the third apparently successful test in as many weeks.
The Scud missile flew about 450km (280 miles) before landing in the sea off its coast, South Korea’s military said.
Observers say the tests indicate the North is making progress towards missiles capable of carrying warheads.
The North has repeatedly defied a UN resolution banning all nuclear and missile activity.
Japan has lodged a protest against the latest launch which it says landed in its exclusive economic zone.
North Korea has a large stockpile of short-range Scud missiles developed by the Soviet Union. Modified versions of the Scud missiles can have a range of 1,000km.
The previous two launches were of medium to long range missiles, both of which the North claimed as “successful” tests.
The first of those launches was hailed by Pyongyang as a new type of rocket capable of carrying a nuclear warhead – it was a demonstration of the North’s longest-range nuclear-capable weapon yet.
Pyongyang has been testing its missiles at an unprecedented pace and experts believe it is steadily edging towards the test of an intercontinental ballistic missile capable of hitting the mainland United States.
North Korea says its weapons programme is necessary to counter US aggression.