Baghdad - The row over the role of Kurdish fighters, or peshmerga, in Iraq came to a head Monday, as officials warned them against operating outside the country's northern Kurdish Autonomous Region.

"If the peshmerga are deployed outside the Kurdish Autonomous Region, it is unconstitutional," said Abdel Karim al-Samarrai, the acting head of the Iraqi parliament's security committee.

The presence of peshmerga in the city of Khanakin, which lies in the province of Diyala, has caused friction, according to a statement from al-Samarrai posted on the website of his party, the Sunni Iraqi Accord Front.

On Saturday, six guerillas were killed and three injured near Khanakin when a peshmerga patrol suffered a bomb attack. The reason for the attack was unclear.

The autonomous region incorporates the provinces of Arbil, Sulaymanyah and Dohuk.

Kurdish parties do not trust the Iraqi national army, and have deployed fighters in several cities outside the autonomous region that have Kurdish populations.

The cities lie between the autonomous region and the capital Baghdad.

During an offensive against al-Qaeda terrorists in Diyala, Iraqi troops were prevented by peshmerga from entering Khanakin, which sits near the Iranian border. (dpa)