Eighteen months ago, in western Afghanistan, a 15-year-old boy picked up what he thought was a packet of food - it blew his head off.



Sayyid Ahmad Sanef believed the bright yellow object lying on the ground near his home was one of the 37,000 plastic humanitarian aid packages of the same colour dropped on Afghanistan by US military aircraft - but it had come from a cluster bomb.



Cluster bombs contain as many as 200 smaller bomblets and up to 30% of these fail to explode on impact but, like landmines, remain deadly for many years.



This is particularly the case when the weapons are dropped from medium or high altitude.



This can cause the bomblets, which contain shrapnel and flammable material, to drift in the wind and land a long way from the intended target.



And they are more likely to kill children, who pick them up without knowing what they are, according to British charity Landmine Action.



The bomblets were mistaken for aid packages in Afghanistan



Director Richard Lloyd told BBC News Online: "As many are brightly-coloured and the size of a drinks can or toy, they are particularly attractive to children."



Nato governments and their military commanders generally argue cluster bombs are an effective and useful weapon in certain circumstances.



The UK military says its L20 bomblets have a "secondary arming device" to ensure any that do not explode immediately on impact do so within 15 seconds.



But Mr Lloyd said: "As we know from Afghanistan, Kosovo and the last Gulf war, these weapons cannot be used in a way that discriminates between civilian and military targets and that is illegal under military and humanitarian international law."



Cluster bombs have killed nearly 2,000 Kuwaitis since the end of the 1991 Gulf war, according to Labour MP Joan Ruddock.



She said last month their use in Iraq would be "inconsistent with the government's pledge to keep civilian casualties to a minimum".



The Americans also dropped about 285 million cluster bombs on Cambodia, Vietnam and Laos, according to the Pentagon.



In August 2000, a quarter of a century after the Vietnam war ended, one of them exploded and killed six children in the central province of Binh Dinh.



They were playing with the device after finding it in a canal

The cluster bomb controversy - BBC