Iran's use of cluster munitions to attack Israel violates the laws of war and may constitute a war crime, according to a Monday report from Human Rights Watch.
Human Rights Watch was able to confirm three separate instances of cluster munitions being delivered by ballistic missiles launched from Iran toward heavily populated areas in Israel. These cluster bombs killed several Israeli citizens, including an elderly couple in Ramat Gan and a construction worker in Yehud.
Most recently, missile fragments hit a parking lot near the Kirya military base in Tel Aviv, which serves as the IDF's headquarters, after Iran launched multiple rounds of cluster munitions at central Israel on Saturday.
“Iran’s use of cluster munitions in populated areas in Israel poses a foreseeable and long-lasting danger to civilians,” said Patrick Thompson, crisis, conflict, and arms researcher at Human Rights Watch. “Cluster munition bomblets are dispersed over a wide area, making them unlawfully indiscriminate in violation of the laws of war.”
Although Human Rights Watch only confirmed three uses of cluster munitions, IDF Home Front Command said as early as March 10 that half of all ballistic missiles Iran has fired on Israel during the current war (which, at the time, was only eleven days) had been cluster munitions.
This is a shift from the June 2025 war with Iran, when occasional missiles were built of cluster munitions, but most were not.
International law and cluster munitions: The case of Israel and Iran
While Human Rights Watch has characterized recent Iranian strikes as war crimes, the legal reality is governed not by a blanket ban but by the application of customary international law.
Neither Israel nor the Islamic Republic of Iran is party to the 2008 Convention on Cluster Munitions, meaning that they are not bound by an absolute, treaty-based prohibition.
“Customary international law does not prohibit the use of cluster munitions per se,” Col. (res.) Dr. Liron Libman, former head of the IDF’s International Law Division, explained in an interview with The Jerusalem Post on March 9.
“Only states that are parties to the CCM have undertaken an obligation not to use, develop, or transfer cluster munitions.”
What are cluster munitions?
Cluster munitions are a type of weapon in which a single munition contains a large number of small bombs, known as submunitions.
When the missile reaches the target area, the warhead breaks open and disperses the submunitions over a wide area.
The submunitions typically weigh around one to one-and-a-half kilograms each, and each is designed to strike a different target. Some explode just before hitting the ground, others detonate upon impact, and some function as mines, exploding only when stepped on.
The operational advantage of cluster munitions is their ability to cause damage across a much larger area compared to a conventional bomb or warhead.
Amir Bohbot, Yonah Jeremy Bob, Sarah Ben-Nun, Tobias Holcman, and Yoav Itiel contributed to this report.