According to reports by the Associated Press, the warhead of a cluster munition opens in mid-air and disperses dozens of smaller explosive devices. These bomblets then fall across a wide radius and detonate on impact.

Military experts say the purpose of such weapons is to cover a large area and increase the likelihood of hitting targets such as vehicles, equipment or military units spread across a battlefield.

However, a major concern is that some bomblets fail to explode immediately. These unexploded devices can remain on the ground for long periods and pose risks to civilians who may accidentally trigger them.

How the weapon works

Israeli authorities said one of the missiles launched by Iran carried a cluster warhead instead of a conventional explosive payload.

According to the Israel Defence Forces, the missile detonated high in the air and scattered smaller submunitions across a wide area.

The warhead exploded about seven kilometres above the ground, releasing roughly 20 smaller bomblets across an area of about eight kilometres.

One of the submunitions reportedly struck a house in the town of Azor in central Israel, causing damage but no immediate casualties.

Israel’s Home Front Command warned residents not to approach unexploded objects that might remain on the ground after such attacks.

Israel says Iran used them

Israeli officials say the weapons were used during recent Iranian missile strikes on Israeli territory.

According to the Israeli military, the missile carrying cluster submunitions was launched toward central Israel during one of Iran’s retaliatory attacks.

Footage from the night of March 5 showed multiple flaming projectiles falling through the sky over central Israel, which analysts say is consistent with cluster munition deployment.

Why cluster bombs are controversial

Cluster munitions are widely criticised because of the risk they pose to civilians during and after conflicts.

More than 100 countries have joined the Convention on Cluster Munitions, a 2008 international agreement that bans the use, production, stockpiling and transfer of such weapons.

However, several major military powers — including Iran, Israel, the United States and Russia — have not signed the treaty.

Human rights groups have repeatedly warned that unexploded bomblets from cluster weapons can remain dangerous long after a conflict ends, sometimes causing injuries years later.

Israel and Iran have both faced accusations in the past over the use of cluster munitions in regional conflicts, according to international rights organisations and previous investigations.

(With inputs from agencies)