RAMADI, Iraq (AP) – Thousands of U.S. and Iraqi troops met little resistance Sunday as they planted new outposts in southern Ramadi, seeking to choke off supplies getting to insurgents who control large swaths of Iraq’s biggest Sunni Arab city.

U.S. commanders said the move wasn’t the precursor to a rumored offensive to drive insurgents from Ramadi – but rather an “isolation” tactic to prevent the fighters from receiving arms and reinforcements from outside.

American forces already controlled other routes into town, and the construction of the two outposts on the south side suggests U.S. and Iraqi commanders are taking a gradual approach to confronting what some call the capital of the insurgency.

Ramadi is one of Iraq’s most violent cities, with roadside bombings and gunbattles happening every day. U.S. patrols have been confined to small sections of the city, and tribal leaders who have cooperated with U.S. forces have been assassinated or forced to flee the country.

Col. Sean MacFarland, commander of the 1st Armored Division’s 1st Brigade, called the two new outposts “lilly pads to push out from” into parts of Ramadi that have gone neglected for months.

The go-slow approach could be an indication the military wants to avoid a full-scale assault like that in nearby Fallujah in November 2004, which angered Sunni Arabs. Iraq’s new unity government is trying to persuade fighters in the Sunni-led insurgency to disarm.

Two long columns of U.S. and Iraqi armored vehicles encountered only scattered opposition late Saturday as they moved in to encircle the southern side of Ramadi, the capital of Anbar province, a huge, restive area to the west of Baghdad.

One soldier suffered a broken leg from a roadside bombing during the night, and insurgents fired two mortar shells Sunday that landed about 500 yards from troops working on the outposts. American soldiers fired back, but no casualties were reported.

“The good news is that we didn’t get as much resistance as we’re prepared for,” said Lt. Col. V.J. Tedesco, commander of the 1st Battalion, 37th Armor Regiment. “I really think the fight will be in the coming days.”

Troops began erecting posts to house Iraqi soldiers expected to patrol the Second Officer’s Quarter – a district of 10,000 people living in homes once set aside for soldiers of Saddam Hussein’s army and officials of his Baath Party.

In addition to providing a base for patrolling, the outposts will give U.S. and Iraqi forces control of all major entrances into this city of 400,000 people.

The Euphrates River blocks access from some directions, and U.S. positions already monitored other entry routes. But the lack of bases to the south allowed insurgents to freely enter and leave, and they often used a nearby abandoned train station to hide weapons.

U.S. commanders confirmed some Ramadi residents fled before the operation, but said the numbers were much smaller than reported by some.

“We are seeing some people leaving, but not an exodus,” MacFarland said. “The numbers are in the dozens to hundreds (of families), not anywhere approaching a thousand.”

According to the United Nations’ IRIN news agency, nearly 1,500 families – or about 10,000 people – fled Ramadi. There was no way to independently determine which number was more accurate.

Prime Minister Nouri al-Maliki likely would prefer to avoid large-scale combat in Ramadi as he tries to bring together Iraq’s often warring ethnic and sectarian communities.

He says he will in coming days present a national reconciliation plan, under which his government already has begun releasing 2,500 prisoners, most of them Sunni Arabs from places like Ramadi.

Sunni Arabs were infuriated by the fighting in Fallujah and many Sunni leaders subsequently called for their community to boycott Iraq’s first election in January 2005.

U.S. commanders are also keen to avoid a repeat of the widespread destruction in Fallujah, which officials are still trying to repair.

The military has urged people to stay in Ramadi while troops try to regain control of its neighborhoods.

“We want (residents) to stay and we’re going to win the city by winning the people. And I don’t mean winning by firing tank rounds in the city,” said Capt. Mike Bajema of Seattle, an officer in the 1st Battalion, 37th Regiment.

He said the new Iraqi army outposts will be a big help. “The army has never been here in the south. This has put a lot of stress on the enemy. He has to be feeling boxed in.”

U.S. commanders say regaining Ramadi will hinge on Iraqi troops. “I don’t need more American forces. I need more Iraqi forces,” MacFarland said.

The Iraqi army will face a daunting challenge in trying to subdue insurgents in Ramadi, where even the American military has struggled.

MacFarland and other leaders say Iraqi soldiers are better prepared now, citing the combat experience of the Iraqi army’s 1st Brigade, 1st Infantry Division, which has fought in several major battles.

But MacFarland also conceded many of the troops may be Shiite Arabs alien to the region, because there have been problems in recruiting and keeping Sunni Arab soldiers in Anbar.

“It’s a little harder to keep their ranks, to be quite honest,” he said.