"They want to reach (Kirkuk's) oil wells and fields," Staff General Ali Ghaidan Majeed, the commander of Iraqi ground forces, told AFP, adding that the move breached an agreement that Kurdish peshmerga forces and Iraqi soldiers would man joint checkpoints.

Jabbar Yawar, the secretary general of Iraqi Kurdistan's peshmerga ministry, had said in a statement earlier on Saturday that the peshmerga were making new deployments in Kirkuk solely in the interest of protecting civilians.

"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," he said.

"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."

Another high-ranking Iraqi army officer told AFP that "after the latest movements of the peshmerga forces, the army is on alert."

"The army sees the move of the peshmerga as a (political) manoeuvre and not to fill any vacuum," the officer said.

Kirkuk province and its eponymous capital, home to Kurds, Arabs and Turkmen, fall within the territory the autonomous Kurdistan region wants to incorporate over 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.