Coalition warplanes have been pounding positions around the capital for days hoping to weaken Iraq's elite units, particularly the 60,000-strong Republican Guard.

US Army officers said Thursday units had advanced to within 15 kilometres (nine miles) of downtown Baghdad and controlled the southern approaches to the capital.

US forces were poised outside the airport, as the war to oust Saddam entered its third week, they said.

But Iraqi Information Minister Mohammed Said Sahhaf promptly denied the reports, saying US forces were not within 100 miles (160 kilometres) of the capital.

A new defiant message from Saddam vowed Wednesday that US and British forces would be repelled if they tried to take Baghdad.

"Many thousands of soldiers are defending the homeland ... and they will not allow them (allied forces) to go into Baghdad without defeating and repelling them," the message read out on state television said.

"We will not be surprised if the enemy surrounds Baghdad in five or 10 days," Defence Minister Sultan Hashem Ahmed had forecast on March 27.

"But he will have to take the city. Baghdad cannot be taken by the Americans or the Britons as long as the citizens in it are still alive."

The Pentagon said Wednesday it no longer considered the Republican Guard's Medina and Baghdad divisions, based south of the capital, to be "credible forces."

At US Central Command base in Qatar, Brigadier General Vincent Brooks announced that the Baghdad division "has been destroyed," a claim immediately refuted by Iraqi officials.

"We will approach Baghdad. The dagger is clearly pointed at the heart of the regime and will remain pointed at it until the regime is gone," Brooks said.

Iraq has repeatedly warned that the decisive battle would be in Baghdad, the capital of five million people where it hopes to engage US-led forces in bloody street-to-street fighting and level the playing field with the technologically superior invaders.

Asked if there would be street battles throughout the capital, Sultan Hashem Ahmed replied: "Certainly ... Our strategy consists of fighting him to the end and everywhere and, thanks be to God, we will meet with victory."

If well-armed troops loyal to Saddam are holed up in civilian areas, allied forces risk being drawn into fighting they have not experienced since the chaotic scenes of Somalia in 1993.

Eighteen US soldiers came back in bodybags after a firefight in the capital, Mogadishu, that also saw 1,000 Somali civilians and militiamen killed.

Air raids on areas where soldiers and civilians live side-by-side would also threaten the high civilian casualties Washington and London strain to avoid, especially in light of Baghdad's propaganda campaign to undermine the coalition's moral legitimacy.

An Iraqi official described a recent suicide bombing by an Iraqi that killed four US soldiers as a "classic method" of guerilla warfare that promised US and British "invaders" even more deadly surprises.

Iraqis live off their courage, the official told AFP. "The Americans are scared of dying, but not us."

US President George W. Bush's father, who led the coalition against Saddam in the 1991 Gulf War, forecast the dangers of fighting in Baghdad in his 1998 book "A World Transformed," co-authored with his national security adviser, Brent Scowcroft.

"We should not march into Baghdad," the elder Bush warned.

"To occupy Iraq would instantly shatter our coalition, turning the whole Arab world against us, and make a broken tyrant into a latter-day Arab hero ... assigning young soldiers to a fruitless hunt for a securely entrenched dictator and condemning them to fight in what would be an unwinnable urban guerrilla war."

SPACE.WIRE