BAGHDAD, Iraq — Iraqis are increasingly calling on U.S. forces to leave their troubled nation, emboldened by a newly elected parliament and the growing presence of their blue-uniformed police forces — even though the new Iraqi leaders say it's too early to talk about a U.S. pullout.

The calls gained momentum when Shiite and Sunni religious clerics called for protests to mark the two-year anniversary of Baghdad's fall, prompting four days of demonstrations across the country.

Tens of thousands of mostly Shiite protesters, largely followers of militant cleric Muqtada al-Sadr, filled central Baghdad's streets Saturday, holding the largest anti-American protest since the invasion. Demonstrations have continued, all echoing the same demand: It's time for U.S. troops to leave.

Still, some Iraqis say it's too early for the Americans to leave because Iraqi forces aren't ready for the daily attacks that have killed thousands in the past two years of the insurgency.

"If the Americans leave Iraq now, the political forces will fight each other in order to get power and the victims will be the Iraqi people," said Rashid Abass, a 61-year-old waiter.

Even the influential Association of Muslim Scholars, which has been accused of ties to insurgents, has called for a timetable for a U.S. withdrawal, not an immediate exit.

But the protests reflect a growing impatience with American troops, viewed here both as protectors and antagonists. Insurgents fueling the conflict direct their rage at U.S. troops and Iraqis seen as cooperating with them. That, in part, has delayed any talk of a pullout, with U.S. leaders saying they will leave only when the Iraqi government asks them to go.

On Sunday, protesters shouted anti-American slogans in Duluiyah, 45 miles north of the capital. A day later, a similar demonstration was held in Baqouba, 35 miles northeast of Baghdad.

Yesterday, in the troubled city of Samarra, tribal, city and religious leaders gathered along with students in the shadow of a spiral minaret, throwing rocks at U.S. tanks and shouting for the Americans to leave.

"The Iraqis will fight until they force (the Americans) to leave and let us live in peace and security," Hassan Neama, 33, said yesterday in Baghdad. "They are the source of all of Iraq's problems. We consider the Americans our enemy, not our savior from the Saddam Hussein regime."

Some Iraqis argue the country is ready to take care of itself, after the Jan. 30 elections, the first free vote in 50 years, and last week's naming of a new prime minister, Shiite Ibrahim al-Jaafari.

But in an interview with CNN's "Late Edition" on Sunday, new interim President Jalal Talabani said he didn't agree with the protests, arguing that U.S. forces were needed in Iraq until the country can rebuild its security forces — something he said could take two years.

In a surprise visit to Iraq yesterday, Defense Secretary Donald Rumsfeld didn't address the topic of a U.S. withdrawal. But he called on the country's new leaders to avoid delays in drafting a permanent constitution and building a strong police and army — a reminder the United States doesn't plan to stay forever.

"Anything that would delay that or disrupt that as a result of turbulence or incompetence or corruption in government would be unfortunate," Rumsfeld said.

The Pentagon is reportedly considering a U.S. troop reduction, from 142,000 to about 105,000 by this time next year.

Other coalition forces have announced pullout plans. Poland's Defense Minister Jerzy Szmajdzinski said yesterday all 1,700 Polish troops will withdraw from Iraq at the end of 2005. South Korean defense ministry officials said earlier this month it would cut its military presence there by 270 troops to 3,270. The last contingent of 800 Dutch troops returned home earlier this month.

President Bush has refused to set a timetable for withdrawal.

Speaking to soldiers yesterday at Fort Hood, Texas, Bush said U.S. troops would come home only once Iraqis are able to control their country.

"Iraqis want to be led by their own countrymen," Bush said. "We'll help them achieve that objective. And then our troops can come home with the honor they deserve."

Also yesterday

Border clash: U.S. troops battled arms smugglers and fighters near the Iraqi town of Qaim along the Syrian border, killing an unknown number of foreign insurgents, the U.S. military said. The local hospital reported at least nine people killed.

Mosul violence: A suicide car bomber killed five civilians and injured four others in the northern city of Mosul, and another car bomb in Mosul wounded four people. In nearby Talafar, a car bomb killed five people and wounded eight, including seven children, the U.S. military said.

Probe requested: Interim Prime Minister Ayad Allawi called on Army Gen. George Casey, the U.S. commander in Iraq, to review the cases of Iraqis being held without charges. In the letter sent two days ago, Allawi specifically mentioned several followers of radical Shiite Muslim cleric Muqtada al-Sadr and a large number of Sunni imams. Allawi proposed the detainee issue be studied by a committee made up of Iraq's ministers of interior, justice and human rights and representatives of the U.S.-led coalition.