BAGHDAD - The Shiite-led government is cracking down on U.S.-backed Sunni Arab fighters in one of Iraq's most turbulent regions, arresting some leaders, disarming dozens of men and banning them from manning checkpoints except alongside official security forces.

The moves in Diyala province reflect mixed views on a movement that began in 2007 among Sunni tribes in western Iraq who revolted against al-Qaida in Iraq and joined the Americans in the fight against the terrorist network.

U.S. officials credit the rise of such groups, known variously as Awakening Councils, Sons of Iraq and Popular Committees, with helping rout al-Qaida in Iraq.

But Iraq's government is suspicious of such groups, fearing their decision to break with the insurgency was a short-term tactic to gain U.S. money and support. The government fears they will eventually turn their guns against Iraq's majority Shiites.

"The continuation of the Awakening Councils as they are now is unacceptable," said Ali al-Adeeb, a close aide to Prime Minister Nouri al-Maliki and a senior member of his Dawa Party.

The effort in Diyala, northeast of Baghdad, began last month as U.S. and Iraqi forces launched an operation against al-Qaida in Iraq and other extremists.

Mullah Shihab al-Safi, commander of Sunni fighters in Diyala, told The Associated Press that many senior leaders of his group had been detained and fighters evicted from their offices. He gave no figures.

The U.S. military confirmed the Diyala actions but gave few details. Fighters were only pushed out of buildings they did not own, a military spokesman, Capt. Matt Rodano, said.

But acting against the Sunni movements could alienate the once-dominant minority Sunni Arabs at a time when overtures to them appear to be making headway.

"We fought the Americans for four years and we fought al-Qaida [in Iraq], too," said al-Safi, a former Iraqi army commando during Saddam Hussein's regime who fought in the 1980-88 Iraq-Iran war. "We are an experienced armed group. We are fully capable of bringing the house down."

Since the rise of the allied Sunni movement, America has spent some $200 million on salaries, equipment and training for the fighters, which now number nearly 100,000. The U.S. goal is for many of them to be integrated into the Iraqi army or police, providing the fighters with long-term incomes.

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