Six Iraqis including three women and two children were killed in a US air strike in the city of Ramadi in Iraq's western Anbar province on Saturday, a doctor at Ramadi hospital said.
A police brigadier said five civilians were killed in the attack. There was no immediate comment from the US military several hours after a request for information.
Doctor Kamal al-Ani said the bodies of six members of a single family killed in the strike had been brought to Ramadi hospital, before being released to relatives for burial. Police Brigadier Hamid Hamad Shuka confirmed there was an airstrike in the south of the city at dawn. He said five civilians were killed in the strike.
A senior US general said earlier this week US and Iraqi security forces were taking "an aggressive, offensive approach" to reclaim Ramadi from insurgents.
Last week dozens of al Qaeda-linked gunmen took to the streets in a brief show of force to announce the city was joining an Islamic state comprising Iraq's mostly Sunni Arab provinces, where the once dominant minority lives.
Shuka said US forces had taken control of the street where the insurgents made their demonstration, ordering some families to evacuate their homes and setting up sniper positions.
Last month Major General Richard Zilmer, commander of US forces in western Iraq, said the mission in the sprawling Sunni province of Anbar was to train Iraqi security forces, not "to win that insurgency fight".
On Friday, gunmen attacked three US military positions in Ramadi with rocket-propelled grenades, mortar rounds and machinegun fire, police said.
Residents reported fresh clashes on Saturday and said US troops were using loudspeakers to order people to stay in their homes. US forces were also blocking entrances to the city.
Prime Minister Nuri al-Maliki and his US backers have been struggling to bring stability to Iraq more than three years after the US-led invasion. Sectarian attacks kill around 100 people a day in tit-for-tat violence blamed on insurgents and militias.