An Iraqi journalist who lives in Jordan has said that 11 members of his family have been killed by Shia gunmen in the Iraqi capital, Baghdad.
Dia al-Kawwaz said his two sisters, their husbands, and seven children were shot at the family home on Sunday.
The police in Baghdad have not confirmed the attack, but one officer told the BBC the killings had occurred.
Mr Kawwaz edits a website that has been critical of the Iraqi government and the US military presence in Iraq.
He has lived outside Iraq for more than 20 years.
On his news website, Mr Kawwaz said the gunmen stormed into his family home in a Shia district of north Baghdad on Sunday, opening fire indiscriminately killing everybody there.
He said the attackers threw explosives into the house before driving off in a vehicle with no number plates, passing unhindered through a nearby police checkpoint.
Mr Kawwaz was unequivocal in accusing Shia militia men of carrying out the attack.
Although it was confirmed unofficially to the BBC, interior ministry director of operations Maj Gen Abdel Karim Khalaf denied all knowledge of the attack.
"This is a lie. Nothing like this has happened. If such a big crime happens, we always launch an investigation," he said in an interview with AFP, which first reported the story.
The BBC's Jim Muir in Baghdad says Shia militiamen have been blamed for many such killings in the past and are believed to have heavily penetrated the Iraqi police.
The killings have been condemned by the Iraqi Association for Journalists' Rights. It called on the government to do more to investigate and prevent crimes against the press.
Paris-based media watchdog Reporters Without Borders, says that at least 206 journalists, technicians or assistants have been killed in Iraq since the US-led invasion of March 2003.
In a separate development, US military officials in Iraq say that 10 suspected insurgents have been killed and eight detained during raids targeting al-Qaeda, north of the city of Samarra.