An Amnesty International spokesperson said: 'We have asked the UK and US governments to confirm that they would not use such indiscriminate weapons because of the threat they pose to civilians. Now we understand why they were silent.

In the face of the glaring evidence of how these weapons affect civilians, we reiterate our call on both governments to undertake not to use them again for the sake of the civilians of Iraq.

They must also explain where and why the weapons were used.'

Each cluster bomb contains up to 200 'bomblets' which spread over a wide area. As many as one in five of these bomblets fail to detonate and can remain a threat to the civilian population for decades.