North Korea claimed that launches of KN-23/Hwasong-11A and Hwasong-11D short-range ballistic missiles (SRBMs) on April 8 and 19, respectively, tested “cluster bomb warhead” (submunition) payloads. Although these were the North’s most specific public references to such missile payloads, it alluded to them in Fall 2022 and has long been assessed by outside analysts to possess them. The new reports underscore the important conventional warfighting roles of North Korea’s SRBM force, which performs many of the key missions traditionally taken on by air forces. The launches also follow through on the mandate of the February 2026 Ninth Party Congress to reinforce SRBM deployments against South Korea. Finally, the North probably wanted to capitalize on the substantial press attention given to Iran’s recent use of submunition warheads to trumpet its similar capabilities.
Information to Date
Early April tests. An unidentified North Korean missile was launched April 7, according to the South Korean Ministry of Defense, reportedly showing abnormal early-stage flight. South Korean and Japanese defense sources then reported the launch of multiple unidentified ballistic missiles from North Korea on the morning of April 8 to a range of 240 km, and the launch of a single missile that afternoon to at least 700 km, possibly on an irregular trajectory. The reported flight characteristics of the latter missile resemble those of the KN-23/Hwasong-11A SRBM.
On April 9, North Korean media reported the April 6-8 testing of an “electromagnetic weapon system, carbon fiber sham bombs scattering…and estimating combat application and power of cluster bomb warhead of tactical ballistic missile,” as well as a “firing for testing the maximum workload of engine using low-cost materials.” The “cluster bomb warhead” was said to have been flown on a KN-23, and the test reportedly “confirmed” that the payload “can reduce to ashes any target covering an area of 6.5~7 hectares [16-17 acres, or 0.065-0.07 sq km] with the highest-density power.”
Mid-April tests. The North launched about five SRBMs on April 19 to a range of about 140 km, according to the South Korean military. The next day, North Korean press reported the April 19 launch of five “improved” Hwasong-11D (HS-11D) small, solid-propellant SRBMs with “cluster bomb warhead and fragmentation mine warhead” to a range of 136 km. The warheads reportedly covered their targets over “12.5-13 hectares [31-32 acres, or 0.125-0.13 sq km] with the very high density.”
Kim Jong Un reportedly supervised the test and said that “the development and introduction of different cluster bomb warheads can meet the operational demand of the KPA [Korean People’s Army] in a more satisfactory and effective way…to boost the high-density striking capability to quell a specific target area as well as the high-precision striking capability.” The warheads reportedly were developed over a five-year period by “a group specializing in research into missile warheads.”
Analysis
“Cluster bomb warheads.” These reports are the North’s most specific public references to submunition (cluster) warheads for its SRBMs, although SRBM drills in October and November of 2022 were reported to have used “dispersion strike” and “dispersion warheads,” which probably also meant submunition warheads. Submunitions provide a longstanding means for missiles to distribute warhead effects across a larger area than possible for a single (unitary) warhead of the same total mass. This can better cover area targets such as airbases or dispersed troops, help compensate for missile accuracy limitations, more effectively disperse chemical or biological agents, and complicate targeting of warheads by missile defenses. Soviet-made Scud and SS-21 SRBMs obtained by the North in the 1980s and 1990s had submunition variants, and North Korea long has been credited with submunition-armed SRBMs.
The new reports are significant in that they specifically associate the KN-23 and HS-11D with submunition and “fragmentation mine” warheads, provide sizes of areas purportedly covered by the warheads’ effects, and in the case of the HS-11D test, provide a photo claiming to show one of those areas. As a rough benchmark, the 1990s US ATACMS Block I SRBM carried a 500 kg submunition warhead that affected an area of about 3.3 hectares [8 acres, or 0.033 sq km] compared to the 6.5-13 hectares claimed for the North Korean SRBMs. Because there is no information on the number, size/weight, composition, and release altitude of the tests, it is difficult to evaluate the veracity or effectiveness of the claimed affected areas, or compare the sizes of the claimed areas for the KN-23 and HS-11D. The photo provided by the North with the HS-11D test shows many very small impacts spread over a circular area, suggesting a “fragmentation mine” warhead distributing many small bomblets fuzed to detonate above ground and shower its target with shrapnel.
Other possible warhead types. It is not clear from the North Korean media reports whether the “electromagnetic weapon system” and “carbon fiber sham bombs” are associated with SRBM launches.
Engine with low-cost materials. The context of the April 9 report suggests that the new engine North Korea fired “for testing the maximum workload of engine using low-cost materials” was associated with the unidentified SRBMs tested on April 7-8, or possibly the KN-23. (It would seem unusual to describe the warhead flown on the KN-23 but not a modified motor.) The large expenditures of SRBMs to be expected in modern conventional conflict, as underscored by the situations in Ukraine and Iran, would certainly put a premium on being able to lower the cost of rocket motor production. But it is unclear what measures are being taken to lower cost, or the degree of cost reduction achieved.
Implications
The North’s conducting and publicizing these tests underscores the important conventional warfighting roles of its SRBM force, which it relies on to perform many of the key conventional missions traditionally taken on by air forces due to longstanding alliance air superiority on the Peninsula. Conventional SRBMs would play a central role in the North’ ability to suppress alliance command/control, staging areas, logistics, airbases, ports, and other targets critical to military operations. This importance was directly recognized in the February 2026 Ninth Party Congress report, in which North Korea endorsed reinforcing SRBM deployments to “greatly increase the density and durability of concentrated attack” against the South. Publicizing the latest SRBM tests shows the North making good on this pledge. Finally, the substantial global press attention given to Iran’s use of submunition warheads in the recent conflict—particularly as a way of penetrating Israeli and US missile defenses—is likely to have motivated Pyongyang to trumpet its similar capabilities at this time.
