(ATTN: UPDATES throughout with remarks by S. Korea, U.S. militaries, more details)
By Song Sang-ho and Kang Yoon-seung
SEOUL, Jan. 17 (Yonhap) -- North Korea fired two suspected short-range ballistic missiles eastward from an airfield in Pyongyang on Monday, South Korea's military said, in the recalcitrant regime's fourth show of force this year.
The Joint Chiefs of Staff (JCS) said it detected the projectiles fired from the Sunan airport at 8:50 a.m. and 8:54 a.m., respectively, and that they flew about 380 kilometers at an altitude of 42 km.
"For more specific information, the intelligence authorities of South Korea and the United States are conducting a detailed analysis," the JCS said in a text message sent to reporters without further elaboration.
"Currently, our military is tracking and monitoring related (North Korean) movements and maintaining a readiness posture," it added.
The latest launch came just three days after the North launched two suspected short-range ballistic missiles into the East Sea that it later claimed to be guided missiles fired by a railway-borne regiment during a firing drill.
Soon after the launch, South Korea's presidential National Security Council held an emergency meeting and called the North's continued weapons tests "very regrettable."
The U.S. Indo-Pacific Command said it was aware of the "ballistic missile launches" but assessed the latest event "does not pose an immediate threat to U.S. personnel or territory or to our allies."
"These missile launches highlight the destabilizing impact of the DPRK's illicit weapons program," it said in a press release, referring to the North's official name, Democratic People's Republic of Korea. "The U.S. commitment to the defense of the Republic of Korea and Japan remains ironclad."
Monday's firing from Pyongyang appears to underscore the North's evolving capabilities to launch missiles from various platforms, including trains, subsurface assets and land-based facilities.
Last week, the North warned of a "stronger and certain reaction" to the United States' recent imposition of fresh sanctions on six North Koreans involved in the regime's weapons of mass destruction and ballistic missile programs.
The North also test-fired its self-proclaimed hypersonic missile on Jan. 5 and on Tuesday last week, ratcheting up tensions amid an impasse in nuclear negotiations with the U.S.