In Baghdad, at least seven people died and a number of others were wounded in a series of bomb explosions. Police also found more bodies in the capital showing signs of torture.
The violence took place as Iraqi lawmakers began debate on a Shi'ite proposal to split the country into autonomous regions.
Sunni lawmakers strongly opposed the measure during the proceedings, fearing the move would divide Iraq and concentrate oil wealth in Shi'ite and Kurdish areas.
The debate on the federalism bill is part of a two-step compromise aimed at ending a political stalemate in the Iraqi parliament. On Monday, lawmakers agreed to create a commission favored by Sunnis that will review the constitution and recommend changes.
Meanwhile, the genocide trial of former Iraqi leader Saddam Hussein was adjourned until October 9 after a stormy session in court. All seven defendants were ejected from the courtroom for refusing to remain silent.
Saddam was the first to be expelled, and his departure sparked a shouting match between the judge and the remaining defendants. This is the third time in the last three sessions that Saddam has been ejected.
Saddam and six co-defendants are charged with carrying out a campaign of genocide against Iraqi Kurds in the late 1980s.
Some information for this report was provided by AFP, AP and Reuters.