Gunmen killed eight members of a Sunni family, including six women, and kidnapped two others in a tense area northeast of Baghdad where Shiite militiamen still operate, officials said.
The ambush was a grisly example of the dangers still facing Iraqis as the new US administration prepares to withdraw its troops.
The gunmen stormed the al-Karawi family’s home late on Thursday and shot the eight victims to death in their sleep, said Brigadier General Abdul-Karim al-Rubaie, the head of the security headquarters for Diyala Province.
He initially said on Friday that the dead included two women but later said there were six women, including one who was only 16 years old. The family was poor and had moved to the Maamil village a year ago to work at brick factories in the area, he said.
The US military said four men, four women and one child died.
Conflicting casualty tolls are common in Iraq where access is limited because of security concerns.
Al-Rubaie declined to speculate on the reason for the attack, saying it was still under investigation.
But Iraqi police officials contacted in the nearby town of Balad Ruz and the provincial capital of Baqubah gave conflicting motives.
One said it was a family dispute while another blamed it on Shiite extremists he said still wielded influence in the area.
They spoke on condition of anonymity because they were not supposed to discuss motives with the media since the case was under investigation.
Such attacks were common during brutal sectarian warfare that peaked in 2006 and 2007 but ebbed after a Shiite militia ceasefire order, a Sunni revolt against al-Qaeda in Iraq and a US troop buildup.
Elsewhere, a bomb hidden inside a traffic police booth exploded on Friday in western Baghdad, killing a seven-year-old boy and wounding his mother, police and hospital officials said.
US commanders have warned the security gains are fragile and said a premature withdrawal of US forces could jeopardize the progress made.
US President Barack Obama, who campaigned on a promise to end the war, has asked the Pentagon to plan for “a responsible military drawdown from Iraq.”
At least 4,230 members of the US military have died in the Iraq war since it began in March 2003, an Associated Press count shows. The latest was an American soldier who died in a vehicle accident on Thursday, the military said.
US and Iraqi officials are hoping provincial elections will more equitably redistribute power on a local basis and stem support for violence.
But ethnic and sectarian tensions have been rising ahead of Saturday’s vote, which is widely seen as a dress rehearsal for national parliamentary elections later this year.
Iraqi Prime Minister Nouri al-Maliki urged voters to go to the polls in large numbers, saying he hoped for a turnout of at least 70 percent.
“The elections are a national and religious obligation,” he said on Friday during an address to members of his tribe in Baghdad.
“The important thing is to vote and to participate in large numbers. We want to be proud and say that the turnout was 70 percent or 80 percent,” he said. “This large turnout would send a message to those who claim there is a gap between people and the government and between people and the political process.”
The prime minister is not running in the elections for local councils but has thrown his support behind an umbrella group that includes his party and is known as the Coalition of the State of Law.