Hundreds of civilian deaths in the US-led invasion of Iraq could have been prevented, says Human Rights Watch.
Cluster bombs are blamed for causing civilian casualties
A new report by the New York-based group, entitled "Off Target", examines the circumstances in which civilians were killed.
It concludes that many deaths could have been avoided if the US and Britain had abandoned what it calls "two mis-guided military tactics".
Cluster bombs and attacks on Iraqi leaders are singled out for criticism.
This is a thorough and thought-provoking report from an organisation with a strong track record in analysing civilian casualties in warfare.
Nobody knows exactly how many Iraqi civilians died in this conflict.
Human Rights Watch did not set out to provide its own figure but to look at the circumstances in which they died.
The organisation says that US and British forces generally tried to avoid killing Iraqis who were not involved in combat.
And it notes that many of the Iraqis' own actions - for example the deployment of irregular and para-military fighters in civilian dress blurred the distinction between combatants and non-combatants.
Significant numbers of civilian deaths occurred in heavy ground-fighting in built-up areas like Nasariya and Baghdad.
But Human Rights Watch raises some serious questions about the way in which specific weapons were employed.
It strongly criticises the use of cluster munitions in populated areas.
It estimates that some 13,000 cluster munitions were fired, containing nearly two million sub-munitions, that could well have killed or wounded in excess of 1,000 people.
Cluster bomb facts
Tail fins cause weapon to spin as it falls
Canister releases bomblets at pre-set altitudes
Typical coverage of traditional weapons ranges from 650 - 1,300 ft
The bulk of these cluster-munitions were fired by US artillery systems and the report says that the US Army needs to learn a lesson that the Air Force has already adopted, namely that cluster munitions cannot be used in populated areas without huge loss of civilian life.
The report also condemns the policy of so-called precision attacks against Iraqi leadership targets.
In 50 such strikes it says no Iraqi leaders were killed but dozens of civilians were.
It points to significant intelligence failings.
"Its no good using a precise weapon " said the organisation's Executive Director Kenneth Roth, "if the target hasn't been located precisely".