Israel says Iran is using cluster munitions. What to know about the weapons

TEL AVIV, Israel (AP) — Israel says Iran has been firing cluster munitions throughout their 10-day war — adding a complicated and deadly challenge to Israel’s already-stretched air defenses.

The warheads burst open at high altitudes, scattering dozens of smaller bomblets across a wide area. The smaller bombs, which at night can resemble orange fireballs, are difficult to intercept and have proven lethal.

Normally restrictive about releasing information on Iranian hits and damage, Israeli authorities in recent days have sought to educate the public about their dangers, which can persist as unexploded bombs on the ground even after civilians leave shelters.

Over 120 countries have signed an international convention banning the use of cluster munitions, although Israel, the United States and Iran are among the nations that have not joined the treaty. The weapon has been used for decades in conflicts around the world, including by Israel when it fought the Iran-allied Lebanese militant group Hezbollah in 2006.

Here’s what to know about cluster munitions:

The bomblets scatter and kill indiscriminately

After what’s called a parent munition is launched, it releases smaller submunitions at an altitude of 7-10 kilometers (4-6 miles). These bomblets scatter across a large area, from several hundred meters (yards) to several kilometers (miles), trading precision for coverage.

Critics worldwide argue that cluster munitions kill or maim indiscriminately, with unexploded bomblets remaining dangerous long after their use. In Israel, they can be especially dangerous because most of the missiles have been aimed at its densely populated center.

“Cluster bombs don’t create real damage to buildings, only people,” said Yehoshua Kalisky, a senior researcher at Israel’s Institute for National Security Studies.

Tough to shoot down

Israel’s Arrow missile-defense system has done a good job intercepting incoming ballistic missiles, Kalisky said. But if cluster munitions are released before the missile is destroyed, there is little that can be done.

Israel’s Iron Dome system is geared toward intercepting smaller rockets fired from short ranges and lower altitudes. But it isn’t designed to destroy the clusters once they’ve dispersed into dozens of bomblets, Kalisky added.

Unlike heavier explosives, the bomblets — often weighing less than 3 kilograms (7 pounds) — are most dangerous to targets like cars, storefronts or people caught outside shelters.

“They pose a particular threat to the civilian population both during and after use, with victims often including a high proportion of children,” according to the Convention on Cluster Munitions.

The submunitions fail to explode more often than other kinds of warheads. Unexploded ordnance can act like a land mine, detonating later and killing indiscriminately.

The Open Source Munitions Portal, which authenticates publicly sourced images of munitions worldwide, has published several images of unexploded submunitions found in Israel this week.

Iran has used them frequently

Most of the damage in Israel has been caused by larger Iranian missiles, but Iran has been using cluster munitions on a “nearly daily basis,” said Lt. Col. Nadav Shoshani, a military spokesman. He says Iran fired similar projectiles during the 12-day war in June.

The military said the Iranian warheads contain between 20 and 24 bomblets with explosives weighing up to 5 kilograms (11 pounds).

The Israeli military’s Home Front Command has distributed flyers warning residents not to touch unexploded submunitions. A public service announcement from police also warned people not to touch anything they see and to call authorities instead.

What Iran is using

According to the Missile Defense Project at the Washington-based Center for Strategic and International Studies, Iran said in 2017 that its Khorramshahr medium-range ballistic missile could carry multiple warheads. The missiles are the largest of Iran’s submunition-dispersing arsenal. Iran also has submunition-equipped shorter range Zolfaghar missiles.

Cluster munitions, including those seen in Associated Press video flying westward toward Israel, can look like falling fireballs — an effect caused by the friction of reentering the atmosphere.

N.R. Jenzen-Jones, director of Armament Research Services, said little open-source information exists about Iran’s cluster munitions beyond state television reports of leaders touring missile factories and videos from military exercises. But videos showing them used last week indicate that some Iranian missiles carrying cluster munition warheads are designed to open at high altitude, scattering them across an area far larger than most military targets.

Design components that disperse them at such heights — including a protective coating on the submunitions that can withstand the heat of atmospheric reentry — appear to show they were built for far less precise use than cluster munitions seen in other conflicts.

“The design seems to scatter submunitions so widely as to suggest it was designed purely as a weapon of terror, scattering its explosive cargo indiscriminately over a wide area,” Jenzen-Jones said.

In July 2025, after the 12-day war between Iran and Israel, Amnesty International said Iran’s “deliberate use of such inherently indiscriminate weapons is a blatant violation of international humanitarian law.”

Broadly banned but still used

Cluster munitions — including those more targeted than Iran’s — are not illegal but are barred by the Geneva Conventions for use in civilian areas. They’re also banned under recent international agreements signed by more than 120 nations.

Cluster munitions were first used by Nazi Germany, when it dropped “butterfly bombs” on the United Kingdom in World War II. The U.S. has used various kinds in Vietnam, Laos, Iraq and Afghanistan, and provided cluster munitions to Ukraine. Russia was accused of using cluster bombs in its 2022 full-scale invasion of Ukraine, a charge Moscow denied.

During a 2006 war in Lebanon with the militant group Hezbollah, the U.N. estimated some 30% to 40% of Israeli cluster bombs failed to explode, leaving southern Lebanon littered with hundreds of thousands of bomblets.

The U.S. State Department said Israel likely used American-made cluster bombs in civilian areas during the 2006 war, after U.N. demining teams found unexploded bomblets in hundreds of locations.

Israel is not using cluster bombs currently, according to a military official who spoke on condition of anonymity under the military’s briefing rules.

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Metz reported from Ramallah. West Bank. Sam Mednick in Tel Aviv contributed.