tension, taking to Twitter to assure that Iraqi forces "cannot and will not attack our citizens." Iraqi commanders initially dismissed troop movements as routine deployments aimed at securing nearby Hawija, recently recaptured from Islamic State militants.

But Shiite militia leaders close to Iran said that they were there to move into the province and had presented a list of demands to Kurdish Peshmerga commanders.

Those demands included a Kurdish withdrawal from positions including the city's K1-military base and oil fields.

"The orders are to surround K1 and oil fields and stop and call on the Kurdish forces to retreat," said a counterterrorism officer who declined to be named because of the sensitivity of the topic. "There are strict orders to avoid violence." But militia commanders took a more combative tone. Anyonewho fights Iraqi forces is "the same as ISIS," said Karim al-Nuri, a spokesman for Iraq's mobilization units. State television said that counterterrorism forces, the 9th Division of the Iraqi army and federal police forces had taken "large areas" of the province without a fight. It said popular mobilization units took positions "outside Kirkuk."

Earlier in the day Col. Ryan Dillon, a U.S. military spokesman in Baghdad had described the situation as "stable" but said the "heightened tension" was distracting from the fight against Islamic State militants.

After recapturing the city of Hawija, Iraqi forces were supposed to deploy to the borders with Syria to stamp out the last pockets controlled by Islamic State militants.

The confrontation with Baghdad has also brought out splits among the Kurds. Earlier in the day,