The US 3rd Infantry convoy is rolling on towards Baghdad
All through the night we listened to the rumble of the convoys heading north and that has continued throughout the day.
The whole of the 3rd Infantry Division of the United States army is moving up towards the outskirts of the Iraqi capital, Baghdad.
Reports we are hearing suggest that some units are within ten miles of the outskirts and some are overlooking Saddam International airport.
I can't disclose exactly where we are but I can confirm that there is a huge amount of American armour and logistical support on the roads.
Pretty much a whole American infantry division is pushing north, closing in on the capital.
These units are encountering fairly limited resistance.
There have been one or two fierce fire-fights but they don't seem to be involving large numbers of Iraqi troops.
US forces faced 200 or 300 Iraqi soldiers around Karbala, at Musayyib there were no more than 2,000.
There are fears of a chemical attack as troops approach Baghdad
It does raise questions as to what has happened to those Republican Guard divisions that were guarding the southern approaches to the capital.
Have they just faded away or are they on the outskirts of Baghdad, waiting to take on the Americans in territory which they believe would be more favourable to them?
Certainly, when you travel along the roads here and look at the number of prisoners that have been picked up and the amount of material that has been seized, the quantities are fairly small.
I keep asking where the burnt-out tanks are, and the hundreds of prisoners you'd expect to see if a division had been destroyed.
There are some unanswered questions.
We are on a very high level of alert here, particularly for any chemical attack.
The unit that I'm travelling with has at least two, so-called 'fox' vehicles' which can detect any chemical attack and these are in action as we approach the capital.
We've been in chemical suits ever since we left Kuwait but when we were coming into Karbala yesterday the commander said he wanted everyone to have their masks closer to them.
As we are heading up the road towards Baghdad, the fact that this could be the last stand where chemical weapons could be used is very much on people's minds
That said, the Americans feel they've made incredible progress, they are pleased with the way things are going, but they are uncertain as to what lies ahead.