Defence Minister Robert Hill said the analysts would not have a direct combat role and would not operate in Iraq, but would contribute to the effectiveness of the air campaign crucial to destroying Iraqi military targets.

"The analysts' job will be to examine and analyse imagery taken by aircraft following air strikes on military targets in Iraq to determine the success of their missions and inform future targeting decisions," Hill said.

The six are to be deployed in the Gulf for up to three months helping coalition air forces to maintain their level of target accuracy and avoid duplication.

"The government's decision is in response to a request from the US central command which values highly the specialist skills of defence imagery analysts," the minister added.

Hill also told reporters that Australia will scale down its naval involvement in the war with the withdrawal of two frigates, the Anzac and the Darwin, at the end of the month.

The frigates, sent to the Gulf before the outbreak of war as part of the UN interception blockade, will be replaced by another warship, HMAS Sydney.

"We don't think at this stage that the workload that will exist at the end of this month would require replacement by two ships," Hill said.

"The work is obviously changing and reducing."

He said the Iraqi port of Umm Qasr was now open and the waterways would soon be fully cleared of mines and explosives.

He also described the progress of the war as good.

WAR.WIRE