A major offensive by US forces began overnight just south of Baghdad, with units from the American 3rd Infantry Division attacked Republican Guard divisions around the city of Karbala.
During the night we witnessed a relentless bombardment - wave after wave of bombers followed by repeated salvoes from rocket launchers. All aimed at Republican Guard units close to the city of Karbala.
Superior military strength seems to be having decisive effect so far
Then, during darkness, US forces moved forward.
There was some Iraqi anti-aircraft fire. But from what we understand, and from what we have been told, resistance has been fairly light so far.
There were periods during the night when there was just no pause from the sound of the bombardment. The whole ground shuddered with the sound of these attacks on positions just up the road.
This may well prove to be a similar story as happened elsewhere. The purpose of this offensive is not to go in and take the city of Karbala, but to move forces further north and closer to Baghdad.
It could be that later in the day there may be some attempt to deal with the forces loyal to Saddam Hussein who are in the city.
The Republican Guard are often billed as elite - but elite is a relative term.
From what commanders here have seen so far, they are not very impressed.
There has been very little return artillery from the Iraqis. The simple reason is, as soon as they use their artillery, that identifies them, and there is counter fire.
Of course, they have no air power, and what they are left to fall back on is harassment and guerrilla-style attacks.
It is believed some vehicles have been destroyed and some elements of the Republican Guard armour have been destroyed - but then their armour is quite outdated and no match for the American tanks.
What I am hearing from American commanders is that the Republican Guard have suffered very significant damage - particularly during recent days during this bombardment.
The really important point is that these Republican Guard units psychologically represent some of Saddam Hussein's power.
If they can be defeated on the southern approaches to Baghdad, that will cause considerable damage to the regime.
And of course that will open the way for US forces to move right up to the outskirts of the capital.
On Tuesday, commanders were saying ground forces were beginning to engage Republican Guard units.
This, they said, was the beginning of the attempt to move on Baghdad - but not to take Baghdad.
There are now huge quantities of American armour and logistical vehicles all on the move - heading north towards the capital.
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