Updated

Retired U.S. Lt. Gen. Jay Garner arrived in Baghdad Monday for his first postwar visit as U.S. forces and Iraqi police kept the peace in a city still largely without power, clean water or a clear political direction.

Garner, who is leading reconstruction efforts in Iraq, is expected to arrange for an interim civil authority in Baghdad.  An Iraqi opposition figure who proclaimed himself mayor days ago and said he had formed a municipal government is not recognized by the United States, Reuters reported.

Mohammed Mohsen al-Zubaidi, a recently returned Iraqi exile, had promised to put on trial anyone whose "hands are stained with the blood of the Iraqi people" under a new constitution based on Islamic law. Where his authority came from, or whether it was actually recognized by any Iraqis, had not been clear.

Garner landed at the former Saddam International Airport after a short flight from Kuwait, 12 days after U.S. tanks and troops secured the Iraqi capital and brought down Saddam Hussein's government.

"What better day in your life can you have than to be able to help somebody else, to help other people, and that is what we intend to do," Garner said upon arrival.

As his plane touched down, black clouds of smoke still drifted through Baghdad's skies from fires set by looters in a lawless city.

The 64-year-old former general, after weeks of preparatory work in Kuwait, came to his new post under tight security and gave little information about planned meetings or travels.

From the airport, he visited Baghdad's 1,000-bed Yarmuk hospital, which was overwhelmed with Iraqi casualties in the final days of the war. Its wards, including the coronary and respiratory care units, were then stripped of almost everything by looters.

"We will help you, but it is going to take time," Garner told doctors.

Some were unimpressed.

"If they give us anything it is not from their own pockets. It is from our oil," said a female doctor, Iman. "Saddam Hussein was an unjust ruler, but maybe one day we could have got rid of him and not had these foreigners come into our country."

Garner arrived with about 20 top aides, including his British deputy, Maj. Gen. Tim Cross. His staff is to grow to about 450 over the next week as others arrive by overland convoy from Kuwait to set up the full Office of Reconstruction and Humanitarian Aid.

The ORHA is to coordinate delivery of outside assistance to the 24 million Iraqis; oversee rebuilding of the nation's infrastructure, in disrepair from a decade of U.N. sanctions, neglect by Saddam's regime and three weeks of U.S. bombing; and oversee the establishment of an interim Iraqi government.

For ordinary Iraqis, however, the first needs are for water and electricity — knocked out during the war — and, especially, for security in a city wracked by almost two weeks of looting.

"We've got a chaotic situation in Baghdad," Adnan Said Youssef, 50, said as he arrived for Easter Mass at a Baghdad church. "The Americans have to take control and end this instability."

As U.S. Marines withdrew in recent days, Army troops moved in to take jurisdiction over all Baghdad and have joined in patrols with a revived Iraqi police force to try to suppress the pillaging and vandalism.

Garner said his priority was to restore basic services such as water and electricity as soon as possible. Garner, who will report to Central Command chief Gen. Tommy Franks, said he intended to complete his work and leave as soon as possible, but declined to give a timeframe.

"We will be here as long as it takes. We will leave fairly rapidly," he said.

In a small sign of returning normalcy, one power plant in northeast Baghdad was operating Monday, providing power to an oil refinery and a nearby district. Traffic lights came to life, though they were temporarily stuck on red.

Stores were open and the streets of Baghdad crowded as residents began sweeping up debris and cleaning their homes. Street vendors hawked chickens,  popcorn and kebabs, and some cafes were open for business.

In Washington, Sen. Richard Lugar, R-Ind., chairman of the Senate Foreign Relations Committee, said installing a strong democratic system will require at least five years because the United States did not plan adequately for the postwar period.

"A gap has occurred, and that has brought some considerable suffering," Lugar said.

The Americans' most difficult challenge undoubtedly will lie in trying to forge a peaceful, cooperative structure among Iraq's political, religious and ethnic factions.

That challenge should become obvious in the coming days, as hundreds of thousands of Iraq's majority Shiite Muslims gather in the holy city of Karbala for an annual feast whose celebration was curtailed under the three-decade rule of Saddam's Baath Party, which was dominated by Sunni Muslims.

Shiite leaders — who are strongly opposed to the U.S. military presence, though pleased to see Saddam go — have called for political demonstrations during the holy days, which run from Tuesday to Thursday.

No Iraqi figures have spoken out in support of a strong U.S. role in the coming months.

Even Ahmad Chalabi, leader of the U.S.-financed Iraqi National Congress exile grouping, has described Garner's job as one of getting Iraq's infrastructure and services back in shape "in a few weeks," after which Iraqis would take over and the Americans would be limited to military roles.

But how Iraq will produce such an interim administration remains unclear. The U.S. government sponsored a meeting of anti-Saddam representatives last week in the southern city of Nasiriyah, but some Shiite leaders and other figures boycotted the session, attended by Garner, in a protest against U.S. influence.

Chalabi said he expects the process of establishing an interim authority, adopting a new constitution and holding free elections to take two years.

Garner, a Vietnam War veteran, was serving as president of a defense contractor, SYColeman Corp., when he was tapped for the Iraq job in January. He ran Operation Provide Comfort, the relief mission to feed and house hundreds of thousands of Kurdish refugees who fled their northern Iraq homes in the wake of the 1991 Gulf War.

The Associated Press contributed to this report.