An influential Washington-backed Iraqi opposition leader meanwhile said the United States must act quickly to bring stability to Iraq and end the influence of Saddam's Baath party.

At the White House, US President George W. Bush on Wednesday allowed himself one brief, private moment of exultation as he watched dancing Iraqis drag a toppled statue of Saddam through downtown Baghdad's dusty streets.

"They got it down!" he said, according to spokesman Ari Fleischer, as he watched television images of US Marines using an armored tank recovery vehicle to tear the once-imposing bronze figure from its pedestal.

But while Saddam's rule over Iraq seemed to have collapsed as fully as the monument in Paradise Square, the White House carefully contained most outward signs of exuberance behind cautious admonitions that the war was not over.

Television images of joyous Iraqis mobbing US soldiers and brandishing US flags are historic and "heartening signs of military progress and mankind's taste for freedom," said Fleischer.

But "we are still in the midst of a shooting war, and men and women are still in harm's way. The war is not over. There remain a lot of dangers ahead."

Vice President Dick Cheney touted the scenes of celebration throughout Iraq as "evidence of the collapse of any central regime authority" and vindication for the US war plan, but warned "hard fighting" may yet lie ahead.

Defense Secretary Donald Rumsfeld sounded a similar tone, comparing the celebrations in Baghdad to to the fall of the Berlin Wall and saying the tide has turned in the three-week-old war.

"Saddam Hussein is now taking his rightful place alongside Hitler, Stalin, Lenin, Ceausescu in the pantheon of failed brutal dictators, and the Iraqi people are well on their way to freedom," he said.

"The regime has been dealt a serious blow. But the coalition forces will not stop until they have finished the job."

Most Americans agree. A Washington Post-ABC News poll published Thursday found that 77 percent felt there was more fighting ahead -- 62 percent feared a long and costly peacekeeping effort in Iraq.

Rumsfeld said the United States did not know whether Saddam survived a coalition airstrike Monday against a building where he and his two sons were believed to have been meeting.

Battles still raged in and around Baghdad and other cities were hotly contested, Rumsfeld and Myers said.

Banned chemical and biological weapons believed still in Iraqi hands also remained to be discovered, Rumsfeld said.

Cheney, speaking to an audience of newspaper editors in New Orleans, Louisiana, refused to predict how long the fighting will last in Iraq.

Last week, Fleischer had said that Bush's "definition of victory" was the point at which the regime is disarmed and its hold on power is broken "so the Iraqi people can be free and liberated."

Meanwhile, Chalabi, head of the Iraqi National Congress, urged US authorities to send their nominated head of an interim civilian administration to Iraq as soon as possible to sort out the country's problems.

The US official, Jay Garner, is currently working in Kuwait. Rumsfeld said the retired general would go to Baghdad only once the fighting has ended.

In the opinion survey, Americans who favor putting the United Nations in charge of Iraq until a functioning government can be formed outnumbered those who believe the United States should be in charge by 53 percent to 37 percent.

And 41 percent were concerned the war would cause "long-term damage" to US relations with countries that oppose the war, such as France, Germany and Russia.

SPACE.WIRE