Baku, April 2, AZERTAC North Korea fired what appeared to be an intermediate-range missile into the East Sea on Tuesday, the South Korean military said, in its third ballistic missile launch of the year, according to Yonhap News Agency.The Joint Chiefs of Staff (JCS) said it detected a missile presumed to be intermediate-range class fired from the Pyongyang region at 6:53 a.m. but did not provide further details."Our military has heightened surveillance and alertness in preparation for additional launches. We are maintaining a full readiness posture while sharing information related to North Korean ballistic missile launches with U.S. and Japanese authorities," the JCS said in a text message to reporters.Japan's defense ministry said the North Korean ballistic missile fell into waters outside Japan's exclusive economic zone.The latest ballistic missile launch comes 15 days after North Korean leader Kim Jong-un guided firing drills involving super-large multiple rocket launchers in the country's western region.The South Korean military said the missiles fired by the North's 600-millimeter multiple launch rocket system flew about 300 kilometers, which could put most parts of the South Korean territory within range. Pyongyang has claimed a tactical nuclear warhead could be mounted on such a weapon.Tuesday's launch marks North Korea's third ballistic missile launch this year. On Jan. 14, the North test-fired a solid-fuel intermediate-range ballistic missile carrying a hypersonic warhead.