North Korean missile tests earlier this month (Picture: KCNA).
South Korea's military says North Korea has fired more missiles into the sea to extend a recent streak of weapons tests.
They are believed to be aimed at pressuring Washington and Seoul over slow nuclear diplomacy.
Pyongyang has ignored South Korean calls for dialogue recently and is seen as dialling up pressure on Seoul to coax major concessions from Washington on its behalf.
South Korea's Joint Chiefs of Staff said projectiles were twice launched from an area on the North's eastern coast, but did not immediately say what the weapons were, how many were launched or how far they flew.
It was North Korea's sixth round of weapons launches since late July, when it began stepping up its demonstrations while expressing frustration over stalemated nuclear negotiations with the United States and continuance of US-South Korea joint military drills that the North sees as an invasion rehearsal.
The White House said it was aware of reports of the launches and was consulting with Seoul and Tokyo.
The North has ignored South Korean calls for dialogue recently and is seen as dialling up pressure on Seoul to coax major concessions from Washington on its behalf.