Shiite Muslims (search) marched through Baghdad for a second day Tuesday, this time demanding the execution of Saddam Hussein (search) -- whose Sunni-dominated regime repressed the Shiite majority for decades.

Five thousand people joined the march that wound its way from Sadr City, a poor Shiite neighborhood in northeastern Baghdad, to Firdous Square, the plaza in the center of the capital where Saddam's statue was pulled down April 9, marking the ouster of the Baathist regime (search).

Saddam was captured Dec. 13 and the Pentagon has designated him a prisoner of war.

"The butcher of Iraq is not a POW. He must be punished," read a banner waved by some demonstrators.

"Saddam is a war criminal, not a POW. Execute Saddam," the crowd chanted, waving huge green flags, the color of Islam.

The march, which coincided with smaller protests in two other cities, came a day after a much larger demonstration of 100,000 Shiites in Baghdad to demand direct elections to replace the U.S.-led interim administration.

Shiites, who are believed to make up about 60 percent of Iraq's 25 million people, were kept out of power during Saddam's 35-year rule by the minority Sunni Muslims. Thousands of Shiites, including clerics, were murdered by the regime. Victims often were buried in mass graves.

Since the fall of Saddam, the Shiites have begun asserting their numerical superiority. Generally supportive of the U.S. invasion last year, Shiite leaders now pose the biggest political challenge to the U.S.-led occupation and its plans for a power transfer this summer.

Leading Shiite cleric Grand Ayatollah Ali al-Husseini al-Sistani opposes the U.S. plan that envisages holding 18 regional caucuses in May to choose a transitional legislature. The assembly would then appoint a provisional government to take power on July 1, formally ending the U.S. occupation.

Al-Sistani wants early, direct elections for the new government. But Washington says it is impossible to hold elections before June 30 because there has been no census and there are no true voter lists.

The precarious security condition makes elections even less feasible, U.S. officials say. The security fears were reinforced by a suicide bombing on the edge of the U.S. compound in Baghdad on Sunday that killed 31 people. A missile believed to be a rocket landed in the compound Tuesday but caused no "significant damage," a U.S. spokesman said.

But recognizing that Shiite aspirations cannot be ignored, the United States on Monday asked U.N. Secretary-General Kofi Annan (search) to send a team to Iraq to determined if elections are possible. Annan said he would consider the request.

U.S. officials hope the U.N. team would conclude that early elections are impossible and convince al-Sistani to drop his demand.

The U.S.-led administration is struggling to bring stability to the country. Saddam loyalists and members of his former Baath Party continue to launch attacks on American troops, although the frequency has dropped since Saddam's capture. A total of 501 U.S. soldiers have died in the conflict.

Saddam is being held at an undisclosed location.

"Since the fall of Saddam, we got our total freedom. We call for the execution of Saddam the infidel, who killed our sons and kept them in mass graves," 40-year-old Karima Hanoun said at Tuesday's demonstration. She said 11 relatives were executed by Saddam.

POW status under the Geneva Conventions grants Saddam certain rights, and many Iraqis fear such status will shield him from a trial in Iraq.

International Red Cross officials have said the conventions would not prevent the United States from handing Saddam over to an Iraqi tribunal, as long as a fair trial is guaranteed.

A statement by the demonstrators said Saddam should be tried by an Iraqi court for crimes against humanity.

"We emphasize our rejection and condemnation of the unjust American decision" to term him a prisoner of war, the statement said. "Did America forget, or is (it) forgetting the screams of the children, orphans, and the tears of women who are crying at the graves of their sons and husbands?" it said.