Hundreds of thousands of Shi'ite pilgrims descended on the Iraqi city of Karbala on Monday to celebrate a religious holiday, amid concerns of more sectarian violence.
Shi'ite Muslims whipped themselves with chains to mark the end of the 40-day mourning period for the Prophet Muhammad's grandson, Imam Hussein, killed in the seventh century.
Thousands of security personnel were deployed in and around the city to prevent a repeat of insurgent attacks that killed more than 170 people during the holiday in 2004.
In other developments, Iraqi police say at least 16 people were killed in attacks around the country.
Meanwhile, President Bush said today he understands the continuing violence in Iraq has shaken the confidence of Americans. But he said there is progress that makes him optimistic about the country's future.
In a speech in the midwestern state of Ohio marking the third anniversary of the U.S.-led invasion, Mr. Bush pledged that U.S. troops will stay in Iraq until the country's new security forces can protect the country's fledgling democracy. He also called on Iraqi leaders to put aside their differences and form a unity government.
The speech, part of a series, came as recent polls indicate flagging public support for Mr. Bush and the war.
Some opposition-party Democrats such as Congressman John Murtha - a retired Marine Corps colonel have said Iraq is in a civil war and U.S. troops should begin withdrawing.
Separately, the U.S. military says soldiers have detained 46 suspected insurgents in coordinated missions with Iraqi security forces in Kirkuk and Hawijah in the last week. A statement says two insurgents were also killed during the mission.