Human Rights Watch accused Iran of possible war crimes for launching ballistic missiles containing cluster munitions at Israel in a report Monday. The cluster bombs are internationally banned because of their inherently indiscriminate nature, as they break apart in midair and disperse over a wide area.

The HRW report documented Iran’s use of cluster munitions against Israel since Feb. 28 that killed 28 civilians, caused damage to civilian infrastructure and left on the ground unexploded ordnance that still poses a threat in multiple locations. The human rights group said these actions may constitute war crimes.

HRW examined about 50 videos, five photos of impacts and other photos of unexploded munitions across the country that had been posted online, as well as interviewed eyewitnesses. After its investigation, it confirmed three cluster bomb attacks on civilian populations that killed two construction workers in Yehud and an elderly couple in Ramat Gan. It also said that a single ballistic warhead dispersing cluster munitions may have produced impacts in Or Yehuda, Bat Yam and Holon.

HRW also said that the unexploded bombs, much like mines, can pose a danger for years to come.

“Iran’s use of cluster munitions in populated areas in Israel pose a foreseeable and long-lasting danger to civilians,” the report stated, adding that at least 16 civilians had been killed in Israel, Judea and Samaria from missile attacks. Meanwhile, about 1,900 civilians in Iran have also been killed, according to the report.

Iran is not a party to the 2008 Convention on Cluster Munitions. However, the report said that does not give it the freedom to fire indiscriminately at civilian population centers without distinguishing between civilians and combatants.

Human Rights Watch urged Iran to immediately cease its use of cluster munitions, saying that cluster bombs are not only illegal because of their indiscriminate nature, but also because they continue to pose a danger to civilians for years — long after the conflict may have ended.