At the temporary headquarters of the British First Fusiliers Y Company, on the site of a former Baath Party compound, soldiers uncoiled rolls of barbed wire atop a perimeter wall, an added layer of defense against potential intruders in this southern Iraqi village.

Outside the compound's front gate, meanwhile, past more razor wire and a sentry positioned behind a sandbagged barricade, another group of British and American soldiers were trying to organize a shipment of food -- tuna fish, milk, biscuits and apple juice -- due to be delivered to needy Iraqis.

The message seemed mixed. Battling a tenacious Iraqi enemy on his home turf and trying to protect their own troops at camps and checkpoints, the British at the same time are trying to mingle with the population and carry out humanitarian chores to create at least the impression that while the war goes on elsewhere, normality is returning to southern Iraq.

It is a complicated dual role for British troops stationed here, who are at once engaged in a guerrilla war and a relief operation, and a role many of them find contradictory and confusing. At night, British troops are subjected to Iraqi mortar rounds and sniper attacks by militiamen with assault weapons and rocket-propelled grenades. By day, some of those same troops are escorting water tankers to villages, inspecting schools and factories for damage, mediating local disputes.

"We shouldn't be doing this," said Sgt. Mac McGuinness of Y Company. "The humanitarian aid has come in too quickly. After everything has been [secured], it should come through, but not at the same time."

McGuinness, a 15-year army veteran with experience in Northern Ireland and Bosnia, said humanitarian operations should typically begin in what is known as Phase 4, the final phase, of a military conflict. Phase 1 is troops ready to move, Phase 2 is troops on the move and Phase 3 is the fighting. In southern Iraq, he said, the troops are still at Phase 3.

U.S. Maj. Douglas Stelmach, a reservist from Buffalo who normally works as an Internal Revenue Service investigator, is here in southern Iraq with an Army civil affairs unit, dispatched to begin the U.S. military's humanitarian aid program in this first part of the country occupied by U.S. and British forces. But Stelmach, the team leader of six reservists, said security problems make his job more complicated.

"It makes it much more stressful," Stelmach said. "You can never really relax." Fighting a war while launching a relief effort, he said, "has never been done before, and it's tricky."

Stelmach and his team travel in unarmored Humvees without mounted machine guns. But when he goes into a village, distributing food boxes or delivering water from a local tanker, he wears his helmet and flak jacket, and he keeps one hand on the 9mm Beretta automatic pistol he keeps strapped to his front. When crowds gather, he said, he worries about snipers or kidnappers.

So far, military efforts to distribute food have been chaotic at best, with near-riots starting in some villages and food boxes being thrown hectically from the backs of trucks.

"We're a little uncomfortable traveling," Stelmach said, patting his flak jacket. "I don't plan on taking this off for a while."

While he carries out his work, other U.S. units, which specialize in psychological warfare, have been roaming the Iraqi lines around Basra with Humvee-mounted loudspeakers that boom out Arabic-language calls for surrender.

The British commanders fighting for control in southern Iraq see the launch of humanitarian operations -- even with the security situation still unsettled -- as key to establishing a sense of normality for the people who live here and to winning their trust. They believe the "hearts and minds" campaign is an essential component of a war launched with only limited public backing at home and billed by Washington and London as a way to liberate and assist the people of Iraq.

But some commanders concede the dual role is confusing for some of the soldiers, particularly those who have been at the front lines of fighting outside Basra, Iraq's second-largest city, whose suburbs are five miles northeast of Mushirij.

"We're still very much here as fighting troops," said Maj. Douglas McSporran, the commander of Zulu Company, whose unit was based in Mushirij doing humanitarian work before being transferred north for an operation involving taking over a food warehouse on the edge of Basra.

"It's very difficult for the soldiers to do," he said. The trick, he said, is "to try not to get too enmeshed in the local community."

One of the Fusiliers, a crew member on a Warrior armored vehicle, said, "The guys find it a bit frustrating."

The ambivalence of the situation seems summed up in the instructions to the troops of Y Company, marked on a board inside the temporary headquarters: "Remember, we are here to reassure the locals," it reads. "Remain friendly, but our posture is robust. If anyone interferes with us, we will deal with them with the necessary aggression and professionalism."

The situation is still so unsettled here in southern Iraq that the United Nations, which had been planning a major relief and reconstruction operation, had yet to get a toehold 15 days after American and British troops entered the country.

"We are not inside," said a U.N. aid official in Kuwait City, interviewed by telephone. The United Nations, she said, is "nowhere, absolutely nowhere. We can't get in because it's too dangerous." She said the United Nations is restricted from entering Iraq until its own security team makes an assessment.

"It's so frustrating," she said. "The idea was you want to work without military escorts."

The port at the tiny town of Umm Qasr, farther south on the Persian Gulf, has been called secure, but with the rest of southern Iraq still violent, she said, "what's the point of going to the port if we can't go beyond?"

Another complicating factor is the lack of indigenous relief groups. Food distribution in this area, as in the rest of the country, has been controlled by the ruling Baath Party. Here in Mushirij, a small food warehouse was discovered in the compound where the Baath Party had its regional office.

With the United Nations nowhere to be seen, the only food and water distributed to villages comes from British troops, with American assistance just beginning through a civil affairs team that numbers just 21. Disaster response teams from the State Department have not yet come, Stelmach said, because "the military is telling us it is not a permissive environment."

A British soldier oversees the distribution of water in southern Iraq close to Basra. British and U.S. forces, though still subject to sniper attacks, are carrying out humanitarian missions.

British soldiers talk to an Iraqi civilian near Basra, where the allied forces are trying create a semblance of normality by mingling with the population while war goes on elsewhere.