LITTLE ROCK, Ark. — Authorities raided medical clinics, pharmacies and other locations across the South on Wednesday as part of a Drug Enforcement Administration attempt to thwart illegal prescription drug sales.

The raids in Arkansas, Alabama, Louisiana and Mississippi were the latest stage of an operation launched last summer by the Drug Enforcement Administration’s drug diversion unit, which has now netted 280 arrests over more than a year, including 22 doctors and pharmacists.

“We have people who have taken an oath to do no harm who are throwing that oath out the window,” DEA Special Agent in Charge Keith Brown said after the early morning raids.

The DEA’s “Operation Pilluted” had focused on the illegal distribution of oxycodone, hydrocodone and Xanax by medical professionals, and does not target addicts.

Agents arrested 48 people Wednesday: 22 in Louisiana, nine each in Alabama and Arkansas and eight in Mississippi.

Since January 2014, half of the overall arrests have occurred in Arkansas. It and the other three states involved in Wednesday’s raids each ranked among the top 11 states for hydrocodone prescriptions in 2014, according to DEA data.

“Arkansas is unfortunately not only not immune from this epidemic, but in some ways, we are a leading cause of it,” U.S. Attorney Chris Thyer said. He said the state has 146 million hydrocodone pills distributed annually.

In Little Rock, agents raided the KJ Medical Center within sight of the DEA’s local office, detaining seven people, and also swept into the Bowman Curve Pharmacy a mile away, where one woman was brought out in handcuffs.