(ATTN: UPDATES with more details in 4th para)
SEOUL, Oct. 4 (Yonhap) -- North Korea fired an intermediate-range ballistic missile (IRBM) eastward Tuesday, the South Korean military said.
The Joint Chiefs of Staff (JCS) said it detected the launch from Mupyong-ri in the northern province of Jagang at 7:23 a.m. and that the missile flew past Japan. It did not provide additional details.
"While strengthening our monitoring and vigilance, our military is maintaining a full readiness posture in close cooperation with the United States," the JCS said in a text message sent to reporters.
The launch marks the fifth of its kind since late last month. Pyongyang last fired an IRBM in January. The Hwasong 12-type missile flew some 800 kilometers at a top altitude of 2,000 km.
The North launched one short-range ballistic missile (SRBM) on Sept. 25, then two last Wednesday, another two the following day and two on Saturday.
The latest saber-rattling came after Seoul and Washington wrapped up their naval exercise, involving the USS Ronald Reagan aircraft carrier, and a trilateral anti-submarine exercise with Japan last week.
The South, the U.S. and Japan have been reinforcing bilateral and trilateral security coordination amid concerns the North could ratchet up tensions by conducting a nuclear test or other provocative acts.