Four mosques in Baghdad were targeted, CNN reported. Car bombs were set off as people left the mosques after Friday prayers, killing 14 people and injured 25.
Four people were killed in bomb attacks elsewhere in Iraq.
Sunni Muslims, a majority in much of the Arab world, are in a minority in Iraq. Under the regime of Saddam Hussein, however, they dominated the government.
Last week, the Islamic State of Iraq, a group affiliated with al-Qaida, claimed responsibility for a series of bombings that killed at least 61 people. Most of the victims were Shiite Muslims in Baghdad, although some of the bombs targeted Sunnis outside the capital.