Five people died during demonstrations over unpaid civil servant salaries and rising tensions with Baghdad in the Kurdish city of Rania in Sulaymaniyah province, according to Miran Mohammad, the provincial health director.
Another person died while undergoing treatment at a hospital, said a security source who spoke on the condition of anonymity because he's not authorized to speak to the media.
Iraqi Kurds have built a semi-autonomous region in northern Iraq with their own regional government, the Kurdistan Regional Government, or KRG, their own armed forces and an oil-dependent economy.
Kurds -- most of whom reside in Middle East countries, including northern Iraq, eastern Turkey, western Iran and small portions of northern Syria and Armenia -- do not have an official homeland or country. They have never achieved nation-state status. In Iraq, portions of the region are recognized by Baghdad.
Some Kurdish security forces were injured in Rania after demonstrators hurled stones and set political party buildings on fire, the source told CNN.
KRG Prime Minister Nechirvan Barzani appealed for calm, in a statement posted on his official Facebook page.
"Your frustrations are understandable, and I hear them," he wrote. "Peaceful expression of views is, of course, a legitimate and democratic right. But violence is never acceptable. I call on all of you to conduct your protests peacefully."
The protests started Monday -- including in the cities of Sulaymaniyah and Halabja -- as Kurdish civil servants demanded unpaid salaries and other demonstrators angrily called for better water, power and othe