Iraqis in several provinces dominated by the country's Sunni Muslim minority halted work and boycotted schools and universities on April 22 to protest what they see as discrimination by the Shi'ite-led government.
Organizers said the protests in the provinces of Salahuddin in central Iraq, Anbar in the west, and Nineveh in the northwest were a warning to the government, which they said had failed to meet protesters' demands.
Sunnis have complained of marginalization since the fall of Saddam Hussein in 2003 following the U.S.-led invasion of Iraq.
They have staged protests against the Shite-led government since December.
The government has made some concessions, but protesters say that this is not enough.
The government postponed provincial elections in Anbar and Nineveh on April 20, citing security concerns.
Based on reporting by AP and Reuters