The revelation came amid a gun battle between Iraqi troops backed by US attack helicopters and fighters for several hours in central Baghdad on Friday.
Iraqi interior ministry data showed 1,850 civilian deaths in Iraq in November, matching a 45 per cent rise in the number of civilian deaths tallied by Reuters.
The violence has its epicentre in Baghdad, despite thousands of US troops being poured into the Iraqi capital.
Iraqi troops backed by US attack helicopters fought fighters for several hours in central Baghdad on Friday.
Iraq's interior ministry data shows 1,850 civilian deaths in Iraq in November
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Two Apache helicopters firing anti-missile flares swooped over Fadhil neighbourhood, a Sunni stronghold in one of the oldest parts of the capital, amid the slow thump of heavy machinegun fire, witnesses said.
On the ground, US and Iraqi troops, raiding the narrow alleyways in the area clashed with armed men who killed one Iraqi soldier and wounded five, an interior ministry official said.
The defence ministry said 43 people were detained and a house was found that appeared to be a field hospital of those fighting US and Iraqi forces.
The US military said Friday's operation in Fadhil by the 9th Iraqi Army Division and US soldiers was aimed at "capturing and denying a safe haven to terrorist forces".
"The targets of these raids are believed to be regularly killing innocent Iraqis and have an active campaign designed to disrupt the peace and stability of the region," it said.
A resident, Abu Omar al-Qaisi, said Iraqi troops and armed men in civilian clothes entered the area at dawn, causing clashes in which several people were killed. He said he helped carry eight bodies into a local mosque.
US forces earlier carried out raids in and around Baghdad, killing two suspected al-Qaeda fighters and detaining 27, the military said in a statement.