Four others who were injured in the strike on two farm houses in the Shaikh Qaddur al-Shahin village early on Tuesday, were detained by US forces, Haidar al-Tamimi, an Iraqi journalist, told Aljazeera.
Residents also say the injured were arrested.
They added that the casualties of the strike were poultry farm workers.
Al-Tamimi said US troops were dropped to the ground after the strike. The soldiers then opened fire at the two farm houses, he added.
The Association of Muslim Scholars said US warplanes bombed a house and a poultry farm in al-Bushahin village in northeast Baquba, then dropped soldiers to kill the survivors of the attack.
AFP reports that an Iraqi police officer, who spoke on condition of anonymity, said the workers had been sleeping in the fields of the village when the attack occurred.
The report was backed by Hadi al-Azzawi from a human-rights organisation in the city of Baquba, while the main hospital in the city said it had received 13 bodies.
Hussam Shamil, a farmer in the area, told AFP that two of his brothers were killed, while his father and another brother were arrested by US forces.
A US military spokesman in Baghdad acknowledged there was an incident in the area but refused to give details, saying the raids were part of an ongoing campaign against members of the al-Qaeda network in Iraq.
Iraqi police are anti-government
fighters' favoured target
Also on Tuesday, a car bomb exploded in a crowded market in the eastern district of Jamila in Baghdad, killing seven people and wounding 18, a police source told Reuters.
In central Baghdad, two people were killed and 28 wounded by a roadside bomb near a market, police said.
The target of the explosion was not clear.
In southern Baghdad, a car bomb parked in a street in al-Saidiya district exploded, wounding five civilians, police said.
Elsewhere in the capital, police Captain Amir Kamil, who provided security for the Yarmouk hospital, was shot to death on Tuesday at a bus station, Captain Jamil Hussein said.
Gunmen riding motorcycles also killed a traffic officer near his house in al-Amara, 290km southeast of Baghdad.
The slain policeman was a former member of Saddam Hussein's Fedayin militia, Captain Raad Musa said.
The attacks against police came a day after armed men in speeding cars killed Brigadier Hudairi al-Janabi, the chief of police in Falluja, 65km west of Baghdad.
Police also said that the bodies of five people, handcuffed with gunshot wounds in the head, were found in different districts of the capital.
In the southern Iraqi city of Basra on Tuesday, a bomber attacked a crowd of pensioners, killing a woman and wounding five others, police said.
Police sources said the attack was on an area where senior citizens gather to get their pensions.
They said two people were wounded and the bomber was the only person killed in the blast.
The Baghdad bombings came
despite a security clampdown
Nuri al-Maliki, the Iraqi prime minister, declared a state of emergency in Basra last month in an attempt to crack down on militias, armed gangs and feuding Shia factions threatening oil exports. But violence has not eased.
In al-Kifl, south of the capital on Tuesday, a roadside bomb directed at a US military patrol killed one civilian and wounded four, according to Iraqi police.
There was no immediate comment from the US military on the incident.
In another incident, police said gunmen opened fire on a car near Hawija, 70km southwest of Kirkuk, killing three members of the same family.
Meanwhile, a US military spokesman in Iraq has confirmed that US forces have carried out wide military operations, against fighters in al-Ramadi, capital of the Sunni Anbar province.
US forces have set up new checkpoints at all entrances and exits of the city to restrict fighters' movements and cut off their supplies.
A car bomb went off in a crowded
market in eastern Baghdad
The US army has said the operations come in the context of continuous efforts to bring back stability to the city.
Mamun al-Alwani, the governor of al-Ramadi city, told Aljazeera on Tuesday that the situation there was calm.
"Stability prevails over the city," said al-Alwani.
"Fighters are not placing pressure on the citizens, and no military operations are being carried out inside residential areas."