North Korea test-fired two medium-range missiles early Wednesday, a media report said, with the United States and Japan condemning the isolated communist state's actions.
"The North launched one missile presumed to be Musudan from areas near Wonsan at around 5:58 am (2058 GMT Tuesday), but it is assumed to be unsuccessful," the Yonhap News Agency report said, quoting a statement from South Korea’s Joint Chiefs of Staff.
The second launch of what was assumed to be another missile of the same type took place at 8:05 am, according to the Joint Chiefs of Staff.
"South Korea and the United States (militaries) are carrying out an in-depth analysis on it," the Joint Chiefs of Staff said of the second launch.
The missiles flew 150 kilometres and 400 kilometres, respectively, the report said.
A US missile expert was downbeat about the possible success of the second launch.
"They will very likely claim this test as a success but having flown only about a tenth of the Musudan's expected maximum range would make it hard to credit it as more than partially successful," said John Schilling, an aerospace engineer.
The Musudan has an estimated range of 3,000 to 4,000 kilometres, meaning it would have the capacity to hit targets in all of Japan and on Guam, the location of huge US military bases.
Four previous launches of Musudan missiles had all ended in failure, the report said.
UN Security Council resolutions prohibit North Korea from using ballistic missile technology.
Japan immediately responded to news of the missile firing with a protest.
The act "simply cannot be tolerated," Prime Minister Shinzo Abe told reporters.
Defence Minister Gen Nakatani expressed "extreme regret" at the move, calling it a "grave provocative act" in light of international security.
The United States also condemned the launches and said it would raise the issue at the UN Security Council.
"We strongly condemn these and North Korea's other recent missile tests, which violate UN Security Council Resolutions explicitly prohibiting North Korea's launches using ballistic missile technology," said John Kirby, a State Department spokesman.