The US military had earlier reported five people dead in what it said was a car-bomb explosion.
Separately, the US military said that an air strike had destroyed a house in the southern city of Basra on Wednesday, killing a fighter, but it did not have reports of civilian deaths.
Al Jazeera said nine people, including six members of one family, were killed in the US raid, which targeted two houses in the Muhandiseen and Garmat Ali districts.
Iraqi police said that the bombing took place in the Shia fighters' stronghold of Qibla, the site of some of the fiercest clashes during a government offensive in the city.
Describing the Basra incident, Lieutenant David Russell, a US military spokesman, said US-led forces directed "aerial fires" against enemy forces fighting Iraqi troops.
He said one person was killed and a house destroyed but provided no further details about whether US or British aircraft were used in the attack.
In other news from Basra, Al Jazeera reported on Thursday quoting the local operations command of the Iraqi army that soldiers had arrested Yousef al-Musawi, the purported leader of a group called Tharullah, and three of his brothers during a raid in the city's centre.
Al Jazeera also said that Mahdi Army fighters were still deployed in a number of districts of Basra despite the peace deal signed recently by Iraqi officials and Muqtada al-Sadr, the Shia leader.