Two Iraqi priests give one another a ceremonial embrace, while Iraqi altar boys sit on the church altar beneath  depictions of Jesus Christ , during the celebration of  Easter mass, at Baghdad's Sacred Heart Catholic church, Iraq, Easter Sunday, April 20, 2003. Some of Iraq's  minority Christians say they may face uncertain times  if Islamic fundamentalist gain political power in the wake of the fall of Saddam Hussein. (AP Photo/Brennan Linsley)

BAGHDAD, Iraq - A longtime Iraqi exile who has proclaimed himself in charge of Baghdad pledged Sunday that the country's new constitution would be derived from Islamic law and promised to try anyone whose "hands are stained with the blood of the Iraqi people."  Mohammed Mohsen al-Zubaidi also announced ambitious plans get Baghdad's civil administration moving again.  "We have met with lawmen to create laws, and to open the courts so that life can begin to take on legitimacy," he said at a news conference. "The security situation in Baghdad is considered first priority in our agenda."  He spoke as U.S. Marines pulled out of Baghdad, leaving the job of maintaining order in the hands of U.S. Army soldiers - with help from a newly resurgent Iraqi police force.

Nearly two weeks after pushing across Tigris River tributaries into east Baghdad, convoys of U.S. Marines headed south to take up new positions while U.S. Army units moved into east Baghdad. The pullout is a drop in the number of U.S. troops in Baghdad, though precise figures were not released. 

Days after al-Zubaidi essentially proclaimed himself mayor, it remained unclear where his authority comes from or if it exists at all. No U.S. forces or officials were present at his news conference, held in a sweltering room that was once the coffee shop of the battle-pocked Palestine Hotel. 

"I was chosen by tribal leaders and educated people, the doctors of the city and other prominent figures," al-Zubaidi said. "We are not a transitional government. We are an executive committee to run Baghdad." 

The Iraqi capital currently has no government. Invading U.S. forces, together with returning Iraqi police, are keeping the peace until they can arrange for an interim civil authority, ostensibly to be led by retired American Lt. Gen. Jay Garner. 

Al-Zubaidi is a deputy of Ahmad Chalabi, a top figure in the Iraqi National Congress, the opposition group long backed by the United States. 

As al-Zubaidi spoke, one of his associates also said police had discovered a house used by Saddam Hussein's intelligence apparatus that contained documents about "people responsible for killing innocent people all over the world." He offered no details. 

Al-Zubaidi said - also without elaborating - that Iraq's new constitution would be based on Islamic law, as are many Arab nations' constitutions to varying degrees. According to the U.S. State Department, Iraq's current constitution makes Islam the official religion but provides for freedom of religion. Saddam's government limited that right in reality. 

The balding, goateed al-Zubaidi, acting as if he was already running the place, congratulated Iraq's Christians on Easter Sunday and expressed sadness to Shiite Muslims about the 7th-century martyrdom of Hussein, a grandson of the Prophet Muhammad. Hussein's death is being mourned this week. 

"Iraq was deprived of these rituals, and people are now free to practice them," al-Zubaidi said. 

He said 22 committees had been formed to administer Baghdad, and people had been appointed to lead them. He also urged people working in Iraq's ministries to return to work and predicted radio, television and the Iraqi News Agency would all be working on Monday. 

He said enough funds remain in government coffers to pay civil servants' salaries, though he didn't say for how long. 

Gen. Jawdat al-Obeidi, whom al-Zubaidi described as his deputy, outlined the discovery of what he called a secret intelligence service house found after a tip from a "good citizen." 

He said police opened safes there and they found "many documents, lists of terrorist networks, intelligence elements, officers responsible for killing innocent people all over the world, assassination attempts, lists of their payments and bank accounts to finance those terrorist networks." 

"We kept these documents and are looking at legal procedures," al-Obeidi said. He had no further information. Behind him stood a former intelligence officer from Saddam's regime who is handling al-Zubaidi's press. 

Added al-Zubaidi: "Every person whose hands are stained with the blood of the Iraqi people will be put on trial." 

Stores were open and the streets of Baghdad crowded Sunday as residents began sweeping up debris and cleaning their homes. The coalition station Information Radio read a statement announcing an 11 p.m.-6 a.m. curfew for the capital. 

"Anyone who violates this curfew will put himself in danger," one announcer said. Another announcer told people not to carry weapons "because you might be considered a threat to coalition forces." 

Dozens of jobseekers milled outside Baghdad's Alwiyah Country Club hoping for work, but it wasn't clear who was taking down their names. "We just want to work. ... anything you want," Ali Kalaf, 22, a student. 

Electrical engineers were holding out hope - yet again - of an end soon to Baghdad's paralyzing two-week power outage, because a break in a pipeline that supplies fuel to the main power plant had been fixed. The pipeline had been breached by an American bomb, said Janan Behnam, manager of the plant. 

Fifty trucks filled with wheat flour, the first substantial convoy of World Food Program aid, arrived in at a Baghdad warehouse complex Sunday after a trip from Jordan. Adnan Said, the leader of the convoy, said it contained 1,400 tons of wheat flour that will be distributed by the WFP. 

In front of the Palestine Hotel, heavily guarded by U.S. forces, about 100 people demonstrated. Many of them were from the Iraqi Communist Party, which announced the reopening of its offices Saturday. 

Read one banner: "Free country, happy people."