Car bombs across southern Iraq and a shooting in the country's north have killed at least 30 people and wounded dozens more.
The blasts Sunday targeted mainly Shi'ite areas south of Baghdad.
Police say a car bomb attack in the Shi'ite holy city of Najaf killed at least seven people in an open market area.
Twin bombings in the southern city of Basra killed six people, while other car bombs exploded in Nasiriyah, Mahmoudiya, Hillah and Kut where at least five people died.
In the northern city of Mosul, authorities say gunmen killed at least four police officers during an attack on a checkpoint.
No group has claimed responsibility for the attacks.
Officials have blamed a recent surge in violence on Sunni Islamist insurgents and al-Qaida's wing in Iraq, raising concern of a return to widespread sectarian violence.