The exiled leader of the biggest Iraqi opposition group called Thursday on Iraqis to converge in the Shiite holy city of Karbala to oppose a U.S.-led interim administration and defend Iraq's independence.

Ayatollah Mohammed Baqir al-Hakim, leader of the Supreme Council of the Islamic Revolution of Iraq, chose the southern Iraqi city and the date — next Tuesday — because of their connections to Hussein, the grandson of Islam's Prophet Muhammad and one of Shiite Islam's most revered heroes.

"I call on Iraqis to converge in Karbala to oppose any sort of foreign domination and support establishment of an Iraqi government that protects freedom, independence and justice for all Iraqis," al-Hakim was quoted by state-run Tehran television as saying.

Council spokesman Abu Eslam al-Saqir confirmed the call had been issued.

"To the Iraqi people, U.S. domination is no better than the dictatorship of the ousted brutal regime of Saddam Hussein," al-Saqir told The Associated Press.

Al-Hakim will return to Iraq soon, his younger brother told The Associated Press, a move that could galvanize his followers.

U.S. officials have expressed strong concerns about Al-Hakim's Supreme Council, claiming it is supported by the Iranian government and fearing it wants to create an Iranian-style Islamic government in Iraq.

The Supreme Council — which claims thousands of its fighters are ready to take up arms — boycotted this week's meeting of Iraqi opposition groups to begin planning for Iraq's future government, charging the U.S. role as organizer "harms Iraq's independence."

The meeting called in Karbala would mark the 40th day after the anniversary of the death of Hussein, who is seen by Shiites as a symbol of freedom who sacrificed himself to resist corruption and tyranny. He was killed in a battle on the plains of Karbala in A.D. 680, and his tomb is in the city.

Shiite Muslims traditionally gather to mark the 40th day after a death.

Also Thursday, al-Hakim's younger brother said the ayatollah will soon return to Iraq.

"He will be in Iraq when the time is suitable and we are waiting for that," Abdul Aziz al-Hakim told the AP in Kut, Iraq, where the council has set up offices, some 40 miles from the Iranian border.

Al-Hakim's return would be a critical moment in attempts to form a post-Saddam Hussein government. It would command the attention of the majority Shiite population, oppressed for years by minority Sunni Muslims from Saddam's Baath party.

The younger Hakim was greeted by thousands of people in Kut, where he said he was visiting to prepare for his brother's return after 23 years in exile.

Analysts say al-Hakim's appeal to religious feeling and imagery is reminiscent of the tactics used by the late Ayatollah Ruhollah Khomeini ahead of the 1979 Iranian Revolution.

"Al-Hakim is resorting to tactics used by Iran's religious leaders in the '70s to topple the pro-U.S. shah: provoking people's religious sentiments and winning their hearts," said leading Iranian political commentator Davoud Hermidas Bavand.

Al-Hakim's brother said his group would work with other opposition parties in the new Iraq.

"I don't know why America is scared of us, we don't want to make a revolution, but we want to create safety and stability in Iraq," he said at council headquarters in Kut. "We are looking forward to establishing a democratic Iraqi government chosen by the people themselves."

The Supreme Council's military wing, the Badr Corps, has thousands of fighters already in Iraq able to go to battle at the call of religious leaders, said Hakim, who is the corps' leader.

He said the forces — who are lightly armed, but may have acquired heavier weaponry since the war — have been ordered not to fight U.S. forces.

The fighters will go into action "when the people are in real danger," Hakim said, and will "stand side-by-side with the people and help them stabilize the country."