Cluster munitions have been a persistent problem for decades. These weapons have unique characteristics that make them a grave danger to civilians. These four fact sheets provide an overview of the cluster munitions problem, the challenges in clearing these weapons, the difficulties and needs of victims, and the role of the Red Cross and Red Crescent Movement in reducing the impact of cluster munitions on civilians. At the time they are used during conflict, cluster munitions can disperse explosive submunitions over very wide areas of up to tens of thousands of square metres. In addition, large numbers of submunitions fail to explode on impact as intended, leaving tens of thousands, and sometimes millions, of unexploded and highly unstable submunitions. As a result, cluster munitions have caused death, injury and suffering among civilians in nearly every conflict in which they have been used. The international community took decisive action to stop the human suffering caused by these weapons by adopting the Convention on Cluster Munitions in May 2008. Governments, the ICRC, the UN and many other organizations are now working to ensure that the treaty is widely ratified and fully implemented.