US forces killed 27 Iraqi fighters in a ground and air pursuit after the Iraqis attacked an American tank patrol north of Baghdad.
US Central Command said an "organized group" ambushed the tanks in Balad, about 60 kilometres from the capital on the main highway north. The statement made no mention of US casualties.
The patrol returned fire and killed a total of 27 assailants in the battle.
Meanwhile, fire blazed on the oil pipeline from Iraq's northern oilfields after what residents said were twin bomb attacks targeting exports through Turkey.
Despite strong denials by an American military spokesman in Baghdad, Turkish Foreign Minister Abdullah Gul confirmed that the blasts were the result of hostile action.