Ten days after U.S. Marines and British troops stormed into southern Iraq, Basra is still under siege. Iraqi army regulars and members of the Saddam's Fedayeen militia have interspersed themselves among civilians, leaving British commandos wondering aloud whether they will have to enter the city and face house-to-house combat with hard-core fighters.

As the stalemate drags on, many soldiers and even some nearby Iraqi villagers are asking: If Basra has proven so difficult, how much more problematic will it prove for U.S. troops to conquer Baghdad, President Saddam Hussein's capital and the seat of his Baath Party power?

"What's going to happen in Baghdad?" said Sgt. Stu Wickham, 34, of Watford, England. "I think it's going to be a problem in Baghdad."

"They said within 48 hours they would enter Baghdad," said an Iraqi employee of an oil refinery outside Basra. "Now after seven or eight days, they can't even enter Basra."

That was not the plan. Basra was supposed to fall in as little as a day, British soldiers say. Its 1.3 million inhabitants, predominantly Shiite Muslims, were considered largely hostile to Hussein and his party. Twelve years ago, during the Persian Gulf War, they rebelled against Hussein. The hope and expectation of U.S. and British war planners was that the same thing would happen again.

It has not. And Baghdad is likely to prove even more complicated on a number of fronts. The capital is larger and more sprawling, and is home to about 5 million people, divided about evenly between Shiite and Sunni Muslims. While Basra is considered a stronghold of anti-government sentiment, Baghdad is the government's home base and is likely to have many more Hussein loyalists willing to confront the U.S. and British invaders.

Also, Baghdad has been fortified by Iraq's best-trained, best-equipped unit, the Special Republican Guard, while the British in Basra say they are confronting mainly irregular forces who drive around in white pickup trucks, sometimes mounted with heavy machine guns in the style of Somali "technicals."

"They seem to us to be just a bunch of hoodlums picking up weapons," said a British soldier who spent the last few days exchanging fire with militiamen in the city. He said the militiamen are driven to the edge of the city in pickup trucks, and they crawl or slink through the fields and along the oil pipelines, moving close to British positions before popping up to take shots with their assault rifles or rocket-propelled grenade launchers.

"They're crap shots," said the soldier, a 37-year-old corporal whose 15 years of urban combat experience includes Belfast, Bosnia and Kosovo.

"I think we're going to have to" go in, he added. "I don't see any other way."

The problem with such warfare, he said, is that foreign troops have difficulty distinguishing combatants from civilians. "That's the problem we've got now," he said. "We don't know the enemy anymore."

British commanders and soldiers said the continued fighting in Basra appears to be orchestrated by a few "intimidators," Baath Party officials and other leaders who give instructions to the fighters and exhort or threaten them to carry out attacks. The British said their artillery strikes into the city, and occasional American air assaults called in by U.S. forward air controllers based at the Basra airport, have been carefully targeted to hit only those identifiable leaders.

"We're targeting the intimidators," said Capt. Richard Coates, general staff officer of the British Fusiliers battle group here.

One such strike came Friday night, when the Baath Party office in Basra was bombed for the second time. The first attack on the office is what apparently prompted crowds of people to go to the streets last week, leading to reports that a popular insurrection was underway.

The nightly attacks on British positions around Basra decreased for a while after that first attack.

"When it was hit the first time, things went a lot quieter, so we tried it again," Coates said.

British commandos have also been launching periodic raids to arrest people believed to be militia or Baath leaders. They staged one incursion into Basra to destroy two statues -- an attempt, commanders say, to demonstrate that while they remain on the edges of the city, the British troops can operate anywhere and at any time.

The British said they are confident they can enter Basra and secure it, even if it means house-to-house combat, because of their experience in urban battlegrounds. But many soldiers said the troops feel hampered by restrictive rules of engagement that make their mission seem more like a peacekeeping operation than a war.

The British troops were issued small cards outlining rules of engagement, which for this mission stipulate that they may fire only if fired upon. Even armed combatants are given a chance to surrender before the British troops are allowed to open fire.

"If they put down their gun, they don't get shot," said Wickham. "We have very strict rules of engagement -- only fire if fired upon. We're a bit confused about that."

Concern over civilian casualties in urban fighting has also affected the way ground troops operate.

Wickham's unit was the first to reach the bridge approaching Basra and was involved in the earliest fighting. On the second day, he said, his men were taking mortar fire from Iraqi positions inside a compound and called for an airstrike. But the request was denied, he said, because higher-ups feared civilian casualties.

"We asked for close air support. It never came," he said. "Someone at the top stopped it."

The soldiers also find themselves splitting duties between front-line fighting and humanitarian chores that would be left to non-governmental organizations if southern Iraq were secure.

"The guys find it a bit frustrating," said Cpl. Michael Farrier, leader of the "dirty dozen" platoon of the Fusiliers' Zulu Company. "One day they're on the bridge fighting, and the next day they're making sure some village has clean water."

Many of the soldiers say privately that U.S. forces are unlikely to show the same patience in Baghdad that the British have shown here. "I personally think they're going to go right into Baghdad," said one, who asked not to be quoted by name. The corporal, on guard duty at the airport gate, put it this way; "The Americans can keep Baghdad. I think we're going to have our hands full here in Basra."

British troops go building to building to try to secure a stronghold at the town of Zubair, west of Basra. An Iraqi child carries a sink past a British tank as residents of Basra flee the city. British forces have surrounded Basra to try to open the way to bring in humanitarian aid.