United States forces advanced to within 20 miles of Baghdad last night after obliterating two divisions of Iraq's Republican Guard, senior military commanders said. But they also warned that the toughest battles could still be ahead of them, inside the Iraqi capital.
US columns converged on the city in a two-pronged assault, with marines crossing the Tigris river at Kut and infantry passing Kerbala, as coalition bombers kept up a fearsome bombardment of the Republican Guard divisions defending the approaches to the city.
Advance US infantry units were reported to be poised to take Saddam International Airport, to the west of Baghdad. "They can see the city skyline," one military official in Washington claimed.
Brigadier General Vince Brooks declared at command headquarters in Qatar: "The dagger is clearly pointed at the heart of the regime."
In the Pentagon, Major General Stanley McChrystal said the Medina division to the south-west of Baghdad and the Baghdad division to the south-east were "no longer credible forces" after days of heavy bombardment.
Coalition military officials warned that the Iraqi regime still had four more Republican Guard divisions to draw on, although those had been broken up in an attempt to reinforce the Medina and the Baghdad divisions and had also been the target of intense coalition bombing.
Early this morning US spy planes were reported to have spotted units of the Republican Guard moving south from Baghdad to block the US advance and reinforce positions around the airport.
Republican Guard forces continued to put up fierce resistance around Kerbala. A US army Black Hawk helicopter was shot down by small arms fire, killing seven of the 11 soldiers abroad. Four others were wounded and rescued.
Yesterday, 50 RAF warplanes were in the air above Baghdad supporting the attack, as 200 US attack helicopters flew raids over the Iraqi positions.
A Pentagon official said: "They've been broken up and we're taking them out one tank at a time. They're sitting ducks."
Gen McChrystal said that the advance was likely to halt before entering Baghdad, in the expectation that diehard supporters of Saddam Hussein will attempt to make a last stand in its streets. "We are planning for a very difficult fight ahead. We're not expecting to drive into Baghdad and take it in a coup de main [a surprise attack] or something like that," he said.
"It is going to be an all-arms battle," a senior military source said. "They want to push through as quickly as they can. Tactically and strategically there will be overwhelming firepower."
Once the US force arrives on the outskirts of the city its commanders hope the vast military presence so close to the heart of the regime may put enough pressure on them to surrender.
Surprise plans may include the use of airborne troops now that several airfields have been secured in western Iraq. At least 1,000 American paratroopers have been flown into the Kurdish region in northern Iraq. Other airborne troops appear to have been held largely in reserve so far, including the 82nd Airborne and the British Parachute Regiment.
Inside Baghdad, there were reports of preparations for sustained street fighting. Residents of western districts have been moved from their homes and replaced by Iraqi paramilitaries.
At least 50 trenches filled with oil have been set alight across the capital in an attempt to deter the air campaign. But military sources in Qatar said they would not affect satellite-guided munitions.
There will be further potential hurdles in the way of the advancing troops. Having penetrated the 50-mile "red zone" around Baghdad, in which US military officials predicted President Saddam might opt to use chemical or biological weapons, advancing forces were told yesterday to don chemical protection suits.
The 1st Marine Expeditionary Force crossed the Tigris at the town of Kut, reporting only occasional fire from the Baghdad infantry division of the Republican Guard, which had suffered days of intense bombardment, including two massive 15,000lb "daisy-cutter" fuel-air bombs.
Gen Brooks said the Baghdad division, which originally had up to 12,000 troops, had been "destroyed".
At the same time, the US 3rd Infantry Division advanced through the "Kerbala gap", between Lake Razzaza and the Euphrates river, and turned north towards Baghdad's outskirts. The Medina armoured division, supposedly the Republican Guard's best, did little to block its advance.
Gen McChrystal said that if the Medina had not been des troyed, they were very near that point. However, a Pentagon official said there were still four more Republican Guard divisions, including the Nebuchadnezzar, parts of which are thought to be still standing between the 3rd Infantry Division and Baghdad.
The remaining Republican Guard units around Baghdad have been subjected to an intense aerial bombardment for at least a week. "They are in trouble _ our attacks will continue until we finish with the task at hand," Gen Brooks said.
A senior Pentagon official said: "We are going to exercise tactical patience. We are not going to go straight in, but we are going to find out where his command and control is, where his Special Republican Guard concentrations are, and we are going to hit those."
He likened the siege of Baghdad to the situation around Basra, where UK troops have sat on the outskirts, striking at "targets of opportunity" while attempting to provide humanitarian assistance.
