Iraq on Monday marked the third anniversary of the US-led invasion with new bombings, more sectarian tension and continued indecision on government.
Iraqi and US soldiers maintain tight security in Baghdad
Bombs killed at least six security staff and a number of bodies were found - apparent victims of sectarian strife.
Security is tight, particularly in Karbala at a huge Shia festival.
US President George W Bush is set to deliver a new upbeat message on Iraq's future, stressing the efforts being made with Iraqis to end the insurgency.
His address, to be delivered in Cleveland, Ohio, later on Monday, is also expected to highlight successes in rebuilding homes and communities and in efforts to restore calm.
But opinion polls in the US have continued to indicate weakening support for the president on Iraq , with a Newsweek survey last Friday suggesting 65% now disapproved of his policy.
Three years ago bombs started falling on Baghdad at the start of a campaign that led to the fall and eventual capture of former President Saddam Hussein.
The third anniversary saw at least two fatal roadside bombings. One of them killed at least four security guards near the town of Musayyib, south of Baghdad.
The other killed two police commandos and two other people in the Baghdad neighbourhood of Karrada.
At least another nine bodies were also found, in the capital and elsewhere, most showing signs of torture - suspected victims of sectarian attacks that have soared since the bombing of a Shia mosque at Samarra last month.
The continuing violence prompted former Iraqi Prime Minister Iyad Allawi to say at the weekend that Iraq was in the grip of civil war - a view played down by the US and UK.
COST OF WAR
Iraqi civilians killed: 32,600-35,700 on 1 March. Police: 1,900. Source: Iraq Body Count campaign group
US soldiers killed: More than 2,300
Other armed forces killed: 205 (103 of whom British)
US forces now in Iraq: 138,000 (UK: 7,800)
Iraqi forces: 235,000 Source: UK defence ministry
Oil production: 1.8m barrels a day. Pre-war: 2.5m
Iraq funding needed to 2007: $55bn (UN+US estimates). Pledged: $38bn
Cost of war to US taxpayer: $248bn. Source: National Priorities Project based on congressional appropriations
A key flashpoint on Monday was Karbala, 110km (68 miles) south-west of Baghdad, where hundreds of thousands of Shia pilgrims have gathered.
They are commemorating the death of Imam Hussein, grandson of the Prophet Muhammad, in the 7th century, which confirmed the Sunni-Shia schism.
Shia pilgrims have been shot at around Karbala over the past week, with about a dozen deaths reported.
Political parties also remain deadlocked over the formation of a new government following December's parliamentary elections.
They have suspended negotiations for another week but on Sunday did agree on a security council to tackle key issues while talks continue.
A major disagreement is over the Shia majority's choice of Ibrahim Jaafari as prime minister.
Mr Jaafari on Monday expressed confidence that a government would be found to solve Iraq's problems.
"The road ahead will be tough but the Iraqi people have demonstrated their bravery, determination and resolve," he wrote in the Washington Post.
"The world should not falter at such a crucial stage in history."
Mr Bush was also upbeat on the eve of the anniversary, praising US troops and saying the US-led strategy would "lead to victory" and create a secure Iraq for generations to come.
"On this third anniversary of the beginning of the liberation of Iraq, I think all Americans should offer thanks to the men and women who wear the uniform, and their families who support them," he said.
In his assessment of the war, US Defence Secretary Donald Rumsfeld warned that leaving Iraq now would be like returning Germany to Adolf Hitler's followers after World War II.