Civilian deaths in Iraq during 2013 were the worst in years, according to the UN and other observers.
Iraqi Prime Minister Nuri al-Maliki has said the military will leave cities in Anbar Province where deadly clashes took place after a Sunni antigovernment protest camp was dismantled.
Deadly clashes have broken out between security forces and protesters in the central Iraqi city of Ramadi.
Iraqi officials say at least six people have been killed in two separate incidents in the capital, Baghdad.
Iraqi security forces have arrested Ahmed al-Alwani, a Sunni lawmaker who had been sought on terrorism charges.
The United States has boosted shipments of Hellfire air-to-surface missiles and Scan Eagle drones to Iraq because of concerns of increasing violence there.
The UN has condemned a rocket attack on a camp housing an exiled Iranian opposition group in Iraq.
Security officials say a car bomb has exploded near a church in the Iraqi capital as Christians celebrated Christmas Day, killing at least 26 people.
A local television station north of Baghdad was stormed by armed gunmen on December 23.
A senior military commander has died while leading an attack on an Al-Qaeda hideout in Iraq's western Anbar Province.
Suicide bombings targeting Shi'ite pilgrims have killed more than 20 people in Iraq.
Hundreds of thousands of Shi'a make pilgrimages to the holy city of Karbala during the 40-day annual commemoration marking the death of the Prophet Muhammad's grandson, Imam Hussein.