Also in Baghdad, armed men broke into a home in the southwestern Jihad neighbourhood and killed five Shia brothers, one of them a policeman, after separating them from their sisters, the security official said.
The women were unharmed. In a similar attack, assailants entered the home of a Shia family in the same area and killed a man and his three sons. "Both were Shia families," the official said, suggesting the attack was sectarian in nature and carried out by Sunni fighters.
The two families were unrelated, the official added, and it was not known whether the assailants were from the same group. Five people were killed and six wounded in clashes between Shia militiamen and members of the Sunni Janabi tribe in the nearby Al-Amil neighbourhood.
The official added that the area had now been secured by Iraqi police. In the province of Diyala, northeast of Baghdad, nine people were killed on Sunday, police said.
Seven of those, including a policeman, were shot in a series of attacks in the provincial capital of Baquba, while in Abu Saida assailants killed two children. In Ramadi, west of Baghdad, a university professor and a student were killed when assailants fired at a passing police patrol.
In Tikrit, armed men killed a hospital security guard, while in the northern oil city of Kirkuk assailants killed a barber.