A Iraqi politician says eight of his bodyguards have been killed during a gun battle with insurgents and helicopter-backed US forces.
The politician, Fawaz al-Jarba, told the BBC seven of his men died at the hands of the US troops.
The troops arrived at his house in the northern city of Mosul after one guard was killed by gunmen, Mr Jarba said.
The US military has confirmed the number of deaths, saying that "three terrorists" were among the dead.
Mr Jarba, a Sunni Muslim member of Iraq's National Assembly, said insurgents had started firing at his house and that his guards fired back. The clashes then came to the attention of US forces.
"The firing was coming from all directions and the Apaches (US helicopters) were bombing," Mr Jarba said. "The terrorists were firing at me. Why did the Americans start doing this too?"
The US military statement said an investigation had been launched into the incident.
The statement said forces from the 3rd Battalion, 21st Infantry Regiment had observed insurgents on a roof near Mr Jarba's house.
Mr Jarba was recently a candidate for parliamentary speaker. He has criticised Iraq's emerging political system for deepening divisions between communities.
In other violence, an oil ministry official, Ali Hameed, was shot dead by insurgents outside his home in Baghdad, the Iraqi authorities said.
In the Sadr City area of the capital, hundreds of people attended the funeral of a senior Shia cleric, Muhammad Allaq, who was killed on Wednesday.
Influential cleric Ayatollah Sistani has appealed for calm
Mr Allaq was an aide to the country's leading Shia cleric, Ayatollah Ali Sistani. He is the latest senior religious figure to be killed in a wave of sectarian violence.
He was shot in the head while driving to Kut, a city 160km (100 miles) south-east of Baghdad, a police colonel said.
On Thursday night, at least two people were killed in a car bomb near a Shia mosque in Baghdad, police said.
Earlier, a suicide bomber killed one Iraqi soldier at an army checkpoint, while two police officers were killed in a roadside bomb in Baquba, 60km (40 miles) north of the capital.
More than 400 people have been killed in a wave of attacks following the formation of a transitional government last month.
Amid the latest violence, Ayatollah Sistani hosted Iranian Foreign Minister Kamal Kharrazi in the city of Najaf.
Both men have called for calm and for Iraq's Shias to resist provocation by the mainly Sunni-inspired insurgency.