North conducted two missile tests on Wednesday morning South Korea's military has revealed. The missiles launched appeared to be an intermediate-range Musudan missile, military officials in South Korea told news agencies.

The second missile launch followed an earlier one on Wednesday morning that failed, Reuters reported, citing sources. It was not established if the second launch was successful.

The first missile was launched from the east coast city of Wonsan, a South Korean official said, the same area where previous tests of intermediate-range missiles were conducted, possibly using mobile launchers.

The pariah nuclear and missile technology nation has been conducting advanced tests in spite of global sanctions. A series of U.N. Security Council resolutions have banned Pyongyang from conducting further tests of its ballistic missile technology.

Following the missile launches on Wedneesday Japan said it registered strong protest against Pyongyang's action that violated a United Nations resolution.

The latest launch however had no effect on Japan's security, Japanese Defense Minister Gen Nakatani said. But he said the move was a "grave provocative action".

Japan had put its military on alert for a possible North Korean ballistic missile launch. South Korea's Yonhap News Agency had reported earlier that Pyongyang was moving an intermediate-range missile to its east coast in preparation for a launch.

South Korean media has projected that the secretive regime has up to 30 Musudan missiles.

US officials have said the first missile launch on Wednesday failed in flight over the sea between the Korean peninsula's east coast and Japan, Reuters reported.

North Korea has done a series of tests on its Musudan missile, which can theoretically fly more than 3,000 km (1,800 miles) and reach any part of Japan and the US territory of Guam.