IRBIL, Iraq – After Islamic extremists swarmed his city this week, Saad Hussein fled here with his wife and six children. But after one night, he was on his way back home to Mosul, hearing that things were quiet there. "What can we do?" Hussein said. "You have to depend on your God."

Another man stood nearby, his two small sons tugging at his belt. He had left Mosul and was waiting to enter Irbil, about 50 miles to the east. "We don't know what will happen in the future," said Ahmed Ali, 31. "The government is not there. It's empty."

As many as 500,000 Iraqis fled Mosul this week after the city was besieged by the extremist group Islamic State of Iraq and the Levant, many of them Sunnis who seemed less fearful of the summary justice that the group is known for than of their own government and the barrage it might unleash in an effort to take the city back.

That many Sunnis would prefer to take their chances under a militant group so violent it was thrown out of Al-Qaida illustrates how difficult it will be for the Iraqi government to reassert control. Any aggressive effort by Baghdad to retake the city could reinforce the Iraqi army's reputation as an occupying force.

"We are afraid it will be the same situation as in Fallujah and Ramadi," said Abu Mohammed, referring to the two cities that have borne the brunt of government airstrikes.

Hospital worker Ammar Saleh, 32, said, "So far, the militants have not harmed any civilians, and they have freed the city from the checkpoints that choke us." But he added: "I can't trust that the gunmen are better than the army.

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