At least 26 people were killed on Tuesday when Iraqi forces and protesters clashed after troops raided their anti-government demonstration camp near Kirkuk, military sources said.
The exchange of gunfire left six troops and 20 protesters dead during a confused raid on the camp in the town of Hawija, at least three military sources in the area told Reuters.
The ministry of defense said in a statement that troops responded after coming under fire from gunmen in the camp, without giving casualty figures.
One of the officers, a brigadier general from the division responsible for the area, told AFP the operation was aimed at Sunni militants from a group known as the Naqshbandiya Army, and that security forces only opened fire after they were fired upon.
But demonstrators said protesters were unarmed when troops opened fire.
A second officer told AFP that 34 Kalashnikov assault rifles and four PKM machine guns were recovered at the scene.
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.