At least two civilians were killed after a motorcycle bomb missed a passing police patrol in Kirkuk [AFP]

At least 17 people have been killed after a series of attacks in predominantly Sunni areas across Iraq, police say. 

10 were killed in a bomb attack that destroyed the house of two policemen brothers and their families in the central area of Hamia on Thursday. Both policemen, two infants and four women were among the dead, according to Iraqi authorities.

Three others died and 17 were wounded after two bombs exploded outside a popular cafe in the predominantly Sunni district of Sadiyah in southwestern Baghdad, the capital.

A police officer was also shot dead in the same neighbourhood.

In Yarmouk, a mostly Sunni district in western Baghdad, armed men shot dead a real estate agent and two of his clients, police said. Iraqi authorities could not identify the motive for the attack.

Also on Thursday, a motorcycle bomb missed a passing police patrol in the northern city of Kirkuk, killing two civilians and wounding five others, Sarhad Qadir, a police commander, said.

Although there were no claims of responsibility for Thursday's attacks, the bombings in Baghdad's Sunni districts suggest suspected Shia armed groups could be retaliating against Sunni fighters, including al-Qaeda, in the country.

At least 190 people have been killed in a wave of attacks since the beginning of the year, raising concerns that the surge in violence and an escalating political crisis might deteriorate into a civil war.