At least 13 people have been killed in attacks across Iraq today, on the eve of the third anniversary of the US-led invasion.
Seven civilians were killed when US forces opened fire
after coming under attack in a Sunni town north of Baghdad.
One woman was among the dead in the town of Dhuluiya, 90km north of the capital.
US forces then detained eight people, while an aircraft bombed the house of one of those detained.
There was no immediate comment from the US military.
In the northern city of Mosul, Iraqi rebels machine-gunned four Iraqis to death in a drive-by shooting.
Two policemen and two local health officials, travelling in a civilian car, died and a third policeman was wounded.
In a second drive-by shooting, this time in Latifiyah, 40km south of the capital, six Shia pilgrims were injured.
In Baquba, northeast of Baghdad, one policeman was killed and 10 injured when their patrol was targeted by a roadside bomb. A woman passerby was also hurt in the blast.
A shepherd tending his flock died near Kirkuk, in northern Iraq, after stepping on an old cluster bomb left over from the 2003 war.
And the corpses of four men, who had been shot to death, were found floating in the water tanks of a water purification plant to the southeast of the city.
Mortar attack in Karbala
A mortar bomb exploded in the Shia city of Karbala this morning, on the eve of a major religious ceremony.
The single mortar attack came as hundreds of thousands of
pilgrims gathered in Karbala to commemorate Imam Hussein, Prophet Mohammed's grandson.
There were no casualties, police said.
The mortar shell fell in a parking lot about 150 metres away from the Imam Hussein shrine.
Shia pilgrims have been running a gauntlet of bullets and bombs as they walked to Karbala for tomorrow's commemoration.
A dozen pilgrims so far have been killed or wounded by roadside bombs and drive-by shootings on their way to the holy city.
At least 8,000 Iraqi police and soldiers have been deployed in the city where up to two million pilgrims are expected.
Iraq's former Prime Minister has said the country is in a state of civil war and is nearing the point when its sectarian violence will spread through the Middle East.
In a BBC interview, Iyad Allawi said that while the point of no return had perhaps not yet been reached, Iraq is moving toward that point.
