N. Korea fires ballistic missiles, says S. Korea

STORY: North Korea fired two ballistic missiles towards the sea off the Korean Peninsula's east coast on Sunday (December 18).

That's according to South Korea and Japan.

South Korea's presidential office "strongly condemned" Pyongyang for escalating tensions.

The country's Joint Chiefs of Staff said the two medium-range missiles flew about 311 miles.

Japan's Vice Defence Minister Toshiro Ino said the missiles appeared to have landed outside Japan's exclusive economic zone.

“North Korea's series of rapidly escalating provocations threatens the peace and security of Japan, the region, and the international community, and must not be tolerated. It violates the (United Nation’s) relevant Security Council resolutions, and Japan has lodged a strong protest with North Korea through our embassy in Beijing and strongly condemned their actions.”

He added that there had been no report of damages.

The North's missile launch comes just days after the country tested a high-thrust solid-fuel engine.

Experts say it would allow for quicker and more mobile launches of ballistic missiles, as it seeks to develop a new strategic weapon and speed up its nuclear and missile programs.

North Korea has conducted an unprecedented number of missile tests this year -- including an intercontinental ballistic missile capable of reaching the U.S. mainland, despite international bans and sanctions.

In November, Japanese officials said North Korea test-fired an ICMB that landed just 130 miles off Japan.

Japan on Friday unveiled its biggest military build-up since World War Two.

The $320 billion plan will buy missiles capable of striking China, and ready it for sustained conflict.