Women clutching babies and men gripping overstuffed duffel bags had gathered Sunday at the Azubayr Bridge, hoping to flee the tumultuous city of Basra, when a signal went up from Iraqi scouts hidden among riverfront mud huts.
Within seconds, paramilitaries in pickups opened fire on the British forces manning the bridge checkpoint. From another direction, mortar shells rained down on the British, whose massive Challenger tanks returned fire.
Caught in the cross-fire, panicked refugees surged toward the British, who struggled to defend themselves, control the crowd and fire back all at the same time.
The skirmish -- in which the Iraqis made use of human shields, mobile weapons and panic -- underscored the problems facing British soldiers as they try to take Basra, Iraq's second-largest city. It also made clear some of the pitfalls U.S. forces would confront in Baghdad.
"In a way, we can't really do an awful lot," said Maj. Peter MacMullen with the 1st Battalion of Irish Guards, sitting on a curb as the firefight raged at the bridge on the edge of town. "The Iraqis work in groups of two or three, driving white vehicles and dressed in civilian clothes. They have no position, they're moving and use the slums to our left and right, making it difficult to fire back."
At the same time, British military leaders say they must move forward.
"We've got to go in," said Maj. Duncan McSporran of the 1st Fusiliers, whose unit secured one of the main bridges into Basra several days ago in a 36-hour operation that included thwarting an Iraqi attempt to blow up the span with explosives.
The British say they expect to enter the center of Basra soon, after a week of shelling it from the perimeter, and are reviewing the tactics used in attacks like Sunday's checkpoint ambush.
Making their deepest incursions yet into the city, the British forces established forward observation posts from which they plan to call artillery strikes against members of Saddam Hussein's Baath Party and paramilitary squads. The British also demolished a number of statues and murals of Hussein, the trappings of the president's omnipresent cult of personality.
And in a raid into southern Basra, British commandos reportedly killed several Iraqi officers. One British Royal Marine also died in the fighting.
The British military says it has now cut in half the number of roving patrols by Iraqi paramilitaries inside the city.
However, Iraqis still control the center of Basra and continue their attacks on the outskirts.
The Iraqi objectives in such skirmishes seem to be at least twofold, MacMullen said: to move Fedayeen Saddam fighters and weapons through checkpoints during the confusion and to intimidate civilians attempting to leave Basra.
Even when troops are able to maintain control, it's very difficult to pick out the enemy as thousands of people stream past, soldiers said.
Some fit a profile, namely well-fed, well-groomed men with expensive watches and nice clothes driving late-model cars -- people well-cared-for by the Hussein regime. Many inevitably slip through the net, yet in some cases, British soldiers said locals have pointed out Iraqi military officials they recognize.
At one checkpoint Sunday about a third of a mile west of the Azubayr Bridge, four Iraqis sat in the dirt with both hands up as British troops trained assault weapons at their heads.
A few feet away, other soldiers unscrewed the side panels of a white, late-model pickup, revealing a plastic bag containing a 3-inch brick of cash. The driver, Ali Zein Abdin, 38, insisted he was a farmer headed for Basra. But the troops said his story didn't check out given his expensive watch and uncalloused hands. They held him for further questioning.
Many people are trying to get into Basra to find missing relatives, carry in needed supplies or return home.
"I'm scared to go to Basra, but I've got to get my family and get out," said Abdulla Aziz, 25, father of five. "I went out to get food and got stuck."
For several days, British forces blocked men ages 20 to 40 from returning, fearing they would join the fight on the side of the Iraqi military. On Sunday, however, several hundred frustrated young men overwhelmed the barrier and surged past the soldiers, chanting pro-Saddam Hussein slogans as they ran. In the chaos, an old man was run over by a donkey cart.
"There is a fear they'll rejoin," said Capt. Sam Devitt of the Irish Guard's 1st Battalion. "But it's a checkpoint, not a blockade. And you're not going to win, after all, if you do that."
British soldiers and Basra residents alike say civilians inside the city or returning there are under enormous pressure from Iraqi soldiers, police and Fedayeen to attack U.S. and British forces. Sometimes they are bribed; other times relatives are held hostage.
"Civilians are afraid to leave their houses because police wearing civilian clothes form patrols with Fedayeen," said Nathim Jaber, 34, a fleeing oil industry worker. "They find people, give them a weapon and force them to fight."
In the past few days, the Fedayeen have started offering people more than $10,000 in promissory notes for signing up, a fortune in Iraq, Jaber said, although the IOUs are probably worthless.
MacMullen said his unit recently stopped a man returning to Basra who said he had to fight the invading forces or his family would be killed. The British refused to let him pass, but a few days later he was killed after he slipped in by another route and participated in an attack.
Fleeing Basra residents said Fedayeen, Baath loyalists, and Iraqi military and paramilitary have taken over schools and other civic buildings for use as bunkers, ammo dumps and tank storage.
Jalal Abdel Karim, 17, said there were now tanks in the recess area of the Al Marbad Elementary School, with gas masks and mortar rounds inside.
Some fleeing Iraqis expressed doubts that U.S. and British forces can defeat Hussein's fighters in house-to-house combat for Basra or Baghdad.
"If they go into Basra, there's going to be a slaughterhouse," said Aris Darraj. "Fedayeen are very good at street wars. I don't think the British and Americans are brave enough."
But McSporran and other members of the First Fusiliers disagreed.
"The difficulty is fighting in the city, but that's what we're trained for," said McSporran, whose unit cut its teeth in Somalia, Kosovo and Cyprus.
At the bridge on the edge of the city Sunday morning, as the sounds of 60- and 120-millimeter mortar rounds rang out, about 300 people surged forward, initially ignoring the British soldiers who shouted at them in English to lie down and stay still.
Then, in a last-ditch effort to communicate, the troops fired their revolvers and machine guns over the villagers' heads. They dropped in their tracks.
Some soldiers ducked behind their tanks, which opened fire. Then an Iraqi shell landed close to a rear British position, toppling an electric tower in a plume of dust and smoke. After several more explosions, an uneasy stillness settled over the checkpoint.
Soldiers called on the villagers to rise from the dirt one by one to be patted down and searched before they headed off in the direction of Safwan, Umm al Qasr and other villages to the south.
Other residents managed to avoid gunfire as they streamed out of Basra.
Mahmoud Qadi, walking with his wife and five children, including their 1-year-old son, Murtada, said he decided to leave after allied airstrikes started hitting targets in the city around 6:30 a.m.
Qadi said he was fortunate the Fedayeen didn't prevent him from departing. "They control every corner of Basra," he said. "I was lucky not to get into a fight with them, otherwise I'd be finished. They use us as human shields. They put us in front, themselves in the back."
Several families and groups of men said they hoped to reach the Kuwait border, where they'd heard there could be refugee camps set up soon.
Walid Nabil Ibrahim, 31, said he was fleeing in part because of the treatment the regime inflicted on him.
As he spoke, he turned his head to reveal his right ear, the top third of which is missing, before removing part of his shirt to show a back disfigured by acid burns. Ibrahim said he was tortured with knives, chemicals and electricity for nothing more than having the wrong identity papers. He said he managed to get out of jail after three years by putting together a payoff.