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The Drug Enforcement Administration and other authorities are raiding pharmacies, pain clinics and other facilities in four states as part of an aggressive crackdown on prescription pain drug abuse, federal law enforcement sources told NBC News.

The morning busts in Arkansas, Alabama, Louisiana and Mississippi are part of a 15-month operation by the DEA drug diversion unit. The sources said 1,000 agents and officers conducted the raids.

A federal law enforcement source told NBC News that "Operation Pilluted" is the "single largest pharmaceutical operation in DEA history." It is focused on the illegal sale and distribution of pain killers, including oxycodone and hydrocodone.

MORE: How Pill Abuse Touches Every Corner of U.S.

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One of the raids in Little Rock took place at KJ Medical Center, where authorities said they arrested one doctor, four staffers and a security guard.

In the last 15 months, 140 people have been arrested, and officers hope as many as 170 others will be arrested Wednesday, according to the sources. The sources said suspects in the operation include doctors and pharmacists.

Gov. Robert Bentley of Alabama, himself a physician, described the doctors suspected in the raids as “an embarrassment to the medical profession.”

“When they choose to overprescribe narcotics to patients, and they know that these patients may be or are abusing them, then they change from being a physician to really being a drug dealer,” he said.

In Arkansas, federal prosecutor Christopher Thyer described one sting in which undercover officers paid $200 to get prescription drugs from a clinic without ever being examined.

He ticked off sobering statistics about prescription drug abuse in his state. Enough hydrocodone is prescribed in Arkansas every year to give 42 pills to every man, woman and child, he said.

“This is not a crime problem,” Thyer said. “This is truly a public health and community problem.”

There has been good news in the fight against prescription-drug abuse: Deaths from prescription-drug overdoses declined in 2012 after a decade-long climb, and they have since leveled off.

Still, an average of 44 die every day from opioids, including Vicodin, OxyContin and Percocet.