It's mid morning in southern Basra. The streets are pulsing with activity.
By Andrew North
BBC News, Basra
Armoured Warrior vehicles have replaced unprotected transport
Taxis, trucks and mini-vans. Some new, some old, wheezing fumes, mixing it with donkey carts and motorbikes.
In amongst them, a small unit of British troops have set up a "snap" checkpoint.
One soldier waves a car or van to the side of the road. Then another - usually the female in the unit - searches the car.
She's on the lookout for weapons or bomb-making materials.
It's the kind of routine operation British troops have been mounting around Basra ever since they invaded three years ago.
But these days, they have to do things a little differently.
No more turning up in soft-skin, unarmoured vehicles - the risk of attack is now too great.
Parked nearby is the intimidating metal bulk of a Warrior armoured vehicle, with a 30mm cannon on its turret. The other troops travel in armoured Land Rovers.
Translators disguise their identities when working with British troops
And the translator working with the troops wears a mask - fearful he will be labelled a collaborator and killed.
The relative calm British forces enjoyed when they first took control here three years ago has gone. The past month has been the deadliest since the 2003 invasion - nine soldiers have been killed.
But it is Iraqis who have paid the heaviest price. Hundreds have been kidnapped and murdered over the past few months.
The situation is still a long way from that in Baghdad, but concern is growing. The kind of bombings and sectarian killings the capital experiences daily are becoming more common here. Last weekend, at least 30 people were killed in one attack.
In response, Iraq's new Prime Minister Nouri Maliki has declared a one-month state of emergency.
For British troops, the threat is now ever-present. So the patrol doesn't hang around. They check two or three vehicles then move on.
Those behind the attacks on British troops are always watching them, explains the patrol commander, Sgt Dave Devlin of the Royal Artillery.
"They'll send a motorbike out. They'll spot your patrol, then make a phone call and then they get a sniper in, in just 10 or 15 minutes. We don't stay long."
Troops come under attack both on the streets and inside their base
There's another reminder of the risks back at their base - inside Saddam Hussein's former palace in the city, which it is believed he never visited.
Mid-afternoon and there are two thumping bangs. A mortar has been fired into the compound, followed by a rocket. There are no casualties.
But such attacks have become a regular occurrence and made life tougher for the troops here.
They've had to abandon their air-conditioned, but unprotected tents and move into buildings around the complex. Some rooms have air-conditioning, but many don't - a serious complaint when outside temperatures are already pushing 50 degrees centigrade in the shade, with summer only just beginning.
Preventing heat casualties is a constant concern for commanders.
The deteriorating security has made it much harder for journalists to report from Basra too.
The last time I was here was two years ago. It was not entirely safe then. There were some areas you wouldn't go. But for the most part, you could walk or drive around the city.
Why things have changed this year is still not entirely clear. Many local people blame a growing power struggle between rival Shia militia factions. Criminal gangs are involved too, fighting for control of lucrative local smuggling businesses in this border region.
British deaths have risen sharply...
The government in Baghdad is particularly concerned about the impact on the oil trade. The Basra region accounts for the majority of Iraq's current oil revenues. Revenues that are already depleted by widespread corruption.
Further instability could make things worse, with one faction suggesting they could try to cut off oil exports if they don't get concessions from the central government.
Some local people say British actions have helped to fuel the violence. But others say the British have not been tough enough, allowing criminal and factional elements to thrive.
"They should have moved against these people earlier," said Hassan, a teacher. "Now it's too late."
British commanders disagree. They say those behind the recent attacks on their troops are on the back-foot now, after a series of raids netted major finds of weapons and
bomb-making materials. The main threat, these officers say, comes from "rogue elements" in local Shia militia groups - particularly from the Mehdi Army, loyal to the radical cleric Moqtada Sadr.
But they admit they can't solve the problem in Basra. What the British military is hoping is that it can start to hand over more responsibility to Iraq's new security forces.
The recently declared state of emergency is being seen as a test of their abilities.
That's partly what explains the recent increase in violence, some British officers believe.
"As we begin the transition to the Iraqi security forces taking the lead, those who have an interest in derailing what we are trying to achieve see this as a moment of weakness," says Major Stuart Nicholson of the Royal Anglian Regiment, who is closely involved in building up new Iraqi units.
His unit is still mourning the loss of two comrades three weeks ago, killed in a roadside bomb attack.
... but Iraqis still bear the brunt of the increase in violence
"A lot of my guys were good friends with those guys," says Major Nicholson.
The pressure is constant. While they are on a night patrol, the Royal Anglian soldiers from A Company are called back - to defend their base at the palace.
It's come under attack again - this time from small arms fire. Other units flood the area around the base. But the attackers escape into the darkness.