Fawwaz al-Jarba, who was elected to parliament in January on a Shia-led alliance ticket only to leave the party a month ago, said seven people - including relatives and security guards - were killed in a firefight when armed men attacked his home in the northern city of Mosul.
Hospital sources said a total of nine people died and two were wounded in the attack on Thursday.
Al-Jarba said he called US forces, who responded with helicopter support.
In a bizarre twist, al-Jarba later accused US forces of storming his house and killing some of his relatives and bodyguards.
"After one and a half hours of shooting, the US forces entered the house and killed six people who were in the house," al-Jarba told Aljazeera.
According to the US military, armed fighters on a rooftop near the house fired at a helicopter that had been called in to investigate. The helicopter returned fire, injuring three.
US soldiers killed
Meanwhile, the Pentagon said two Task Force Baghdad soldiers died from wounds sustained when their convoy was fired upon by unknown fighters in another vehicle in central Baghdad on Thursday evening.
A spate of murders has stoked
sectarian tensions in Iraq
An earlier military statement said a US soldier was killed after his convoy struck a roadside bomb in the southeast of the capital on Thursday morning.
"The soldier died en route to a military hospital," a military statement said.
The US military also reported a fatality from combat on Wednesday. "A soldier assigned to the 2nd Brigade Combat Team, 2nd Marine Division, II Marine Expeditionary Force (Forward), was killed 18 May during an indirect fire attack on Forward Operating Base Ramadi.
"The 2nd BCT is a US army unit assigned to II MEF (Fwd) in support of Operation Iraqi Freedom," the military said.
In other violence on Thursday, a bomber drove a car at an army checkpoint, killing an Iraqi soldier and wounding eight, an Interior Ministry official said.
Another Iraqi soldier was killed and three wounded in another bomb explosion in the south of the capital, security officials said.
Official, engineer killed
A top Iraqi oil official has been killed outside his Baghdad home.
Zoellick said officials must
condemn sectarian killings
Oil Ministry employee Ali Hamid Alwan al-Dulaimy, 31, was walking out of his house to his car when three men firing pistols from a Kia minibus killed him, his brother, Ahmed Hamid Alwan al-Dulaimy, said in a telephone interview.
The engineer was killed in Kazimiyah, northern Baghdad, on the way to Baghdad University, where he was studying, his brother added.
In Baquba, north of Baghdad, two policemen were killed by a bomb, while a police officer and his father were killed in a drive-by shooting in Samarra, 125km north of Baghdad, police said.
In the Samarra incident, armed men assassinated police officer Omar Majeed Shakir al-Dosh and his father on Thursday, police Lieutenant Qassem Mohammed said.
An Iraqi commando was also killed and another wounded in clashes with fighters in eastern Samarra, and the body of a 40-year-old Iraqi contractor was found near Makhoul, 200km north of the capital.
On Wednesday, armed men shot dead Shia cleric Mohammed Tahir al-Allaq, representative of Grand Ayat Allah Ali al-Sistani in the Jurf al-Nadaf area near al-Madain, about 20km southeast of Baghdad, police Lieutenant-Colonel Shakir Wadi Hamoud said.
Sunni and Shia clerics have been
targeted in recent days
Hamoud said al-Allaq, imam of al-Jawadain Mosque in the predominantly Shia al-Baladiyat neighbourhood of New Baghdad, was killed while driving to Kut, a city 160km southeast of Baghdad.
In Baghdad, US Deputy Secretary of State Robert Zoellick, on a day's visit to Iraq, urged Iraq's new Shia-dominated government to condemn a recent string of sectarian murders.
"With the recent upsurge in sectarian violence, it's important for the leaders of this country to stand up and say something about this," Zoellick said after meeting Prime Minister Ibrahim al-Jaafari on Thursday.
In another development likely to increase tensions with US forces in the country, Shia cleric Muqtada al-Sadr has called on Muslims to paint US and Israeli flags at the entrance to mosques for worshippers to walk on, in protest against the alleged desecration of the Quran at the US detention camp in Guantanamo Bay.
Iraqis at several Shia mosques in Baghdad and the city of Najaf started painting the flags on Thursday.