The Paras are taking no chances in Basra
Soldiers of the Parachute Regiment are pushing deeper into Iraq's second city of Basra to consolidate Sunday's British advance.
BBC correspondent Ben Brown has moved from house-to-house alongside the Paras.
These are some of Britain's most elite soldiers.
They have been sent in to take the heart of Basra.
On Sunday, British Challenger 2 tanks and Warrior armoured personnel carriers advanced very fast through the city, capturing several square kilometres and key buildings.
On Monday, commanders decided it was Parachute Regiment infantry who should go in on foot to take control of the centre of the city, including the old town - partly because its narrow winding streets are not suitable for armoured vehicles.
We are now following a foot patrol which is pushing its way forward kilometre by kilometre, block by block, building by building.
There has been, from what we have heard, no resistance whatsoever - so far at least.
That is not to say there will not be later on.
The troops are alert, they are very heavily armed - some of them carrying anti-tank missiles, heavy machine guns - and they are backed up by Challenger 2 tanks.
It's very hot and dusty here. The Paras do not run - but they are turning and being very watchful.
It looks rather like a foot patrol in Northern Ireland. They are being very cautious, watching behind their backs.
British troops search for Iraqi militia
There is a helicopter gunship up above us now - and then another, and a third.
A soldier in front of me now is raising his gun, looking up at a building.
They are obviously extremely vigilant because they know a lot of militia fighters - nearly all of them - have been fighting in civilian clothes.
It is very easy for a Saddam militiaman to just put down a weapon, become suddenly a civilian - then pick it up again and be a militia fighter.
The enemy of these troops is pretty invisible, especially as the Parachute Regiment have just been brought in to Basra so it is territory they don't know.
I think in some ways it is probably quite frightening, but they must be pleasantly surprised there has been so little resistance so far.
I have heard a few explosions - a very few compared to Sunday where there was very heavy fighting indeed.
The Paras are simply walking along the pavements of broad avenues, walking through large numbers of Iraqi civilians who are sometimes giving them the thumbs up and sometimes, the thumbs down.
There have not been any scenes of wild jubilant celebration - but most people from what I can observe, do seem pleased to see the British soldiers.
Although many locals are more interested in looting from buildings that have been fought over and abandoned.
We are seeing children pushing office chairs down the road, donkeys loaded with fridges, ovens.
People are running off with everything from electric fans to tables and chairs - anything they can get their hands on, they are stealing.
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