Cluster munitions are opposed by many individuals and hundreds of groups, such as the Red Cross, the Cluster Munition Coalition and the United Nations, because of the high number of civilians that have fallen victim to the weapon. Since February 2005, Handicap International called for cluster munitions to be prohibited and collected hundreds of thousands of signatures to support its call. 98% of 13,306 recorded cluster munitions casualties that are registered with Handicap International are civilians, while 27% are children.
The area affected by a single cluster munition, known as its footprint, can be as large as two or three American football fields . A single unguided M26 MLRS rocket can effectively cover an area of 0.23 km˛. In US and most allied services, the M26 has been replaced by the M30 guided missile fired from the MLRS. The M30 has greater range and accuracy but a smaller area of coverage. It is worth noting that for reasons including both danger to civilians and changing tactical requirements, the non-cluster unitary warhead XM31 missile is, in many cases, replacing even the M30.
Because of the weapon's broad area of effect, they have often been documented as striking both civilian and military objects in the target area. This characteristic of the weapon is particularly problematic for civilians when cluster munitions are used in or near populated areas and has been documented by research reports from groups such as Human Rights Watch, Landmine Action, Mines Action Canada and Handicap International. In some cases, like the Zagreb rocket attack, civilians were deliberately targeted by such weapons.