The BBC's Brian Hanrahan: "US fighters are continuing to fly"

The pull-out is due to begin by the weekend, but a US defence spokesman said sufficient forces would remain in the region.

These will include an aircraft carrier, 200 aircraft, more than 20 ships and 20,000 troops.

The scale-back comes despite two attempts by President Saddam Hussein's forces to shoot down Western planes over no-fly zones.

On Wednesday the US said it blasted an Iraqi missile site after an attack on British warplanes patrolling the southern exclusion zone.

Baghdad, which confirmed it had opened fire on patrolling aircraft, accused the US of firing at an Iraqi village killing a farmer and wounding two others.

Major Joe LaMarca: "We're confident we offered the proper response"

This was firmly denied by the United States.

Major Joe LaMarca, a spokesman for US Central Command in Florida said US and British aircraft were conducting a routine patrol at about 0630 GMT when the Iraqis fired six to eight surface-to-air missiles from a site southwest of Talil.

UK Defence Secretary George Robertson: "We are not going to be intimidated"

The US responded to the ''unprovoked attack'' by firing two Harm missiles and dropping a number of laser-guided bombs, he said.

Iraq said it "almost certainly'' shot down ''a hostile plane", but Major LaMarca said all the Western planes had returned safely to their bases.

Second attack in days

The incident came two days after Iraq fired three missiles at US warplanes in the northern no-fly zone.

USS Enterprise - getting ready to leave

US pilots responded by destroying the site with missiles and six laser-guided bombs. Iraq said four people were killed and seven injured.

Iraq has made clear it regards the air exclusion zones as part of its own territory and refuses to acknowledge America or the UK's right to patrol them.

Earlier Iraq called on the United Nations Security Council to debate the no-fly zones.

The BBC's Jonathan Marcus: "Iraq's air defences may pay heavily for each challenge"

The Iraqi ambassador to the UN, Nizar Hamdoon, said the exclusion zones were illegal and not supported by UN resolutions. He warned Iraq would defend itself against further US and UK patrols.

During Operation Desert Fox, two carriers, the USS Carl Vinson and the USS Enterprise, about 40 ships, 350 aircraft and 29,900 troops were in the region.

The USS Enterprise carrier group is set to depart for the Mediterranean by the end of the week.

Sanctions death toll

Meanwhile, Baghdad has again drawn attention to the cost of eight years of international sanctions.

Iraq's Health Ministry says more than one million children and old people have died since sanctions began.

The mortality rate among children under the age of five has increased 16-fold since the embargo with 6,369 dying in November, it said.