At least 20 people have been killed in battle between protesters and security forces, according to ministry of defense.
The clashes broke out early on Tuesday morning when security forces entered an open area in Hawijah, west of Kirkuk, where demonstrations have been held since January.
Iraq's ministry of defence said, in a statement, that 20 armed men were killed along with three army personnel - one officer and two soldiers - in the blasts.
The statement also said that the armed men used protesters as cover, and that the army has arrested 75 "fighters" and seized 40 rifles, plus grenades.
Sheikh Abdullah Sami al-Asi, a Sunni provincial official, said the fighting began when security forces entered the protest area in the town and tried to make arrests.
Al Jazeera's Jane Arraf, reporting from Baghdad, said the protests "started in December sparked by the arrest of a major Sunni politician."
The demonstrations are because "a lot of people are being arrested under a very vague and sweeping anti-terrorist law; a lot of these sweeps are happening in Sunni areas," she added. "They are also upset they have no jobs; a lot of Iraqis here were stripped of their jobs because they were affiliated with the former Ba'ath Party."
A United Nations spokeswoman in Iraq, Eliana Nabaa, confirmed that there were multiple casualties. She urged both sides to immediately lay down their weapons.
Two soldiers were killed and seven wounded in the operation, they said.
Protesters have taken to the streets in Sunni-majority areas for more than four months, calling for the resignation of prime minister Nouri al-Maliki and decrying the alleged targeting of their minority community by the Shia-led authorities.
Army officials accuse the protesters of attacking several checkpoints in the area.
Source: AJ English