As US armoured columns broke out from positions in western Baghdad where they had spent the night, journalists based at the city centre Palestine Hotel watched the battle unfold.
BBC Correspondent Paul Wood filed this report for BBC News Online just before the hotel was hit by a US tank shell which killed two journalists and injured at least three more:
Several journalists were injured when the hotel was targeted
This is a sustained engagement, a battle really, which is closer to us and louder than it has ever been before.
Looking out towards the west of Baghdad from our hotel room, we can see this morning two American fighting vehicles on a bridge across the Tigris.
We saw intermittently, white plumes of smoke shooting up from presidential sites - we believe that was Iraqis attacking American positions.
All sorts of rumours were swirling around - that the Iraqis were attacking Americans who had taken up residence in the Rashid hotel the night before.
Roar of jets
That might have been the case, or it might have been the Americans breaking out of their positions to take care of whatever opposition there is in the west of Baghdad, to move towards the east.
American military sources are saying it is an attempt to link up the US marines in the east with the US 3rd Infantry coming from the west
Every so often, we see American fighter planes very low in the sky - there is the roar of the jet engines.
US tanks stationed on a bridge in central Baghdad
We have heard the sound of helicopters - they might be Apaches, we don't know - that is the rumour.
We have seen American A10 tankbusters flying over and firing on targets - spitting fire out.
Bizarrely, I can see traffic driving down on the streets even as the sound of battle is going on.
Late last night, I visited the Iraqi positions where the fighting is now. There were some people in army uniforms, but very few. It was mostly irregular forces - Baath party militiamen and Saddam Fedayeen.
They were fairly young guys who looked pretty inexperienced. Some of them were just in jeans and T-shirts - not even in any kind of uniform at all.
They had rocket-propelled grenades, they had Kalashnikov rifles.
We are looking at lightly-armed militia forces, the true believers, the party faithful, those who believe in President Saddam Hussein and not the kind of forces I think who can put up resistance to an American armoured column - and are not in any position to stop it.
We have wondered if the final battle for Baghdad started on Saturday with the first incursions
Another explosion. We don't know what it is - this seems to be going on in the western side of Baghdad.
We have unexplained sounds of explosions behind us to the east and that lends credence to the theory that the Americans are trying to link up the US marines from the east with the infantry from the west.
We have wondered if the final battle for Baghdad started on Saturday with the first incursions.
I think - we cannot say for certain - that these are the final hours. It certainly feels like it. That is what people are saying, colleagues of mine, people from other news organisations - that it is going to finish today.