Kurdish security forces deployed near the disputed northern Iraqi city of Kirkuk, a Kurdish official said on Saturday, a move allegedly aimed at combating militants in the area.
In the past week, a wave of violence has killed more than 200 people, including 40 in Kirkuk.
"After consultations with the governor of Kirkuk, there has been a decision for peshmerga (security) forces to fill the vacuums in general, and especially around the city of Kirkuk," Jabbar Yawar, secretary general of Iraqi Kurdistan's peshmerga ministry, said in a statement.
"The intelligence service of the peshmerga has information that terrorist groups have plans to launch terrorist attacks in these regions," Yawar said. "Our only goal is to preserve the life of citizens."
But the Iraqi army ascribed different motives to the deployment.
"After the latest movements of the peshmerga forces, the army is on alert," a high-ranking army officer told AFP. "The army sees the move of the peshmerga as a (political) manoeuvre and not to fill any vacuum."
Kirkuk province and its eponymous capital, home to Kurds, Arabs and Turkmen, fall within the territory the autonomous Kurdistan region wants to incorporate, despite strong objections from the federal government in Baghdad.
Diplomats and officials say the territorial dispute between Baghdad and Kurdistan - a three-province region with its own government, security forces, borders and flag but which still receives a portion of the federal budget - is a major threat to Iraq's long-term stability.