SEOUL — 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 that it detected the projectiles fired from the Sunan airport in the capital in the morning, in a text message sent to reporters. It did not elaborate further.

The missiles were fired at 8:50 a.m. and 8:54 a.m. (2350 and 2354 GMT Sunday), respectively, and that they flew about 380 km at an altitude of 42 km. "For more specific information, the intelligence authorities of South Korea and the US are conducting a detailed analysis," the JCS said without further elaboration

"Currently, our military is tracking and monitoring related (North Korean) movements and maintaining a readiness posture," the JCS said.

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.

Monday's firing from Pyongyang appears to underscore the North's evolving capabilities to launch missiles from various platforms, including trains, subsurface assets as well as land-based facilities.

The US Indo-Pacific Command said it was aware of the "ballistic missile launches" but assessed the latest event "does not pose an immediate threat to US personnel or territory or to our allies."

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 US. — Agencies