Last month, other soldiers from the regiment set up ambushes and conducted information-gathering patrols near the distant village of Gabiyah and its environs to catch, or at least identify, members of gangs of masked men in Iraqi police uniforms who have been driving Sunni villagers from their homes.
Elsewhere, less orchestrated detentions are taking place when strong evidence warrants.
"We're going to continue to communicate that sectarianism isn't going to do anyone any good," says Lieutenant Colonel Rod Coffey, commander of the regiment responsible for Al-Muqdadiyah and its surrounding areas. "Also, we are simply going to arrest any IP [Iraqi police] that breaks the law.
"Now if an IP breaks the law it's generally because he is doing something sectarian -- kidnapping or something. So we are going to continue to arrest corrupt IPs, and that's corrupt not just in the economic sense but also in the sectarian sense."
Al-Muqdadiyah is around 100 kilometers north of Baghdad. It's about 60 percent Sunni, and like most other areas of the country it was roiled by the explosion of sectarian violence following Al-Qaeda's bombing of a Shi'ite shrine in Samarra in 2006. Incidents of violence resulted in Sunnis who lived in mixed neighborhoods fleeing to Sunni enclaves for safety. Shi'a in the city did the same. Militias from both sides devastated the once-thriving market town, and Al-Qaeda took advantage of it all, muscling in and setting up training camps and storage facilities in the nearby countryside as part of its self-declared Islamic State of Iraq caliphate.
U.S. and Iraqi security forces have since driven Al-Qaeda and nationalist insurgent groups from Al-Muqdadiyah and Diyala Governorate, but the legacy of chaos and bloodshed -- sectarianism -- remain and top the agenda of occupying coalition forces.
"The main obstacle to this population adhering to the government and being willing to work within the system, in this area the only hurdle to that that I see is sectarianism within the police," Coffey says. "And that sectarianism within the police is sometimes not overt sectarianism. It's unintelligent reaction to the presence of Al-Qaeda [in the past.] They still associate a cluster of Sunni towns as, 'Oh, they must still be Al-Qaeda,' but people in those towns suffered as much under Al-Qaeda as Shi'ite towns."
Stirring the sectarian pot in Al-Muqdadiyah have been kidnappings by criminals cells believed to include Iraqi police. There have been 14 kidnappings of Sunnis since January and a number have occurred at Iraqi police checkpoints along main roads at night. The result has been an increase in fear and distrust among Sunnis in Al-Muqdadiyah, who now avoid traveling at night on main roads on the outskirts of the city.
"I think there are many IPs that want to do the right thing. They have shown it. Even the people we talk to on our patrols say it," said Captain Mike Stinchfield, the Hawk Company commander who cordoned off Al-Askari. "We don't need to dismantle the IPs, just rid it of some criminal elements.
"There have been many incidents of IPs stopping kidnappings taking place but not turning people in. Many of them are scared of the others."
Stinchfield and 200 men searched the Al-Askari district for kidnappers last week after Iraqis passed information on possible suspects. With them was an informant, camouflaged in U.S. uniform as if an interpreter. Two men (one in possession of nearly a dozen police identity cards) were arrested and turned over to Iraqi authorities for prosecution, but six others detained were later released because evidence against them wasn't strong enough.
The result may seem little for the effort, but U.S. officials are confident it will at least dampen the criminal activity while they continue to try to pinpoint the criminal gangs. Also, during the cordon and search of the community, all military-aged males were whiteboarded -- photographed, fingerprinted, and retinal scanned. That information was entered into a database together with their personal information, such as address, which can be used in future investigations.
"There was a lot of sectarian activity [by police] before," says Iraqi police General Muhammad Abad, who is trying to recruit more Sunnis into the force. "We're trying to get rid of that."
Stinchfield said there would be more special detention raids on Al-Askari and elsewhere in Al-Muqdadiyah in addition to regular presence patrols. "This was a soft-knock operation," the captain says. "There was no kicking down doors or any of that. The men know to treat the people with respect. That's what we have been doing for a long time and it pays dividends. People open up, telling us things."
The total number of police in Al-Muqdadiyah and its immediate environs is about 1,800. The vast majority are Shi'a, a situation that came about after Sunnis boycotted elections in 2005. Those elections gave the Shi'a control of the provincial government as well as the national government, and the police are under the authority of the national Interior Ministry.
Other measures to shore up the police include whiteboarding of all officers, unannounced visits by U.S. troops to police offices and checkpoints, and advanced training of officers. Civilian contractors from the U.S.-based Dyncorp oversee the "democratic policing" training, which is conducted by specially trained Iraqi instructors.
"We're advisers. We twist and tweak," a U.S. police adviser with Dyncorp said at a recent graduation ceremony for about 40 students.