The action, which occurred on Saturday, came one day after the agency suspended the license of drug distributor Cardinal Health Inc, prohibiting it from shipping such products from its facility in Lakeland, Florida. Cardinal immediately obtained a restraining order allowing it to continue shipments pending a hearing on February 13.

Florida's drug enforcers have been cracking down on pharmacies for several years, but this is the first time they have targeted a major chain.

Mark Trouville, special agent in charge of DEA's Miami bureau, said at a press conference that last year the two pharmacies, located 5.5 miles apart in Sanford, about 30 miles south of Orlando, ordered 3 million doses of the painkiller oxycodone. That compares to an national average of 69,000.

Trouville said the pharmacies either knew, or should have known, that a large number of the prescriptions it filled were not issued for a legitimate medical purpose. Red flags the pharmacies should have recognized included misspelled drug names, irregular dosing instructions and phony telephone numbers on prescriptions, he said.

In some instances, four or five people dropped off identical prescriptions from the same doctor at the same time, paid for by one person.

CVS Caremark Corp said that it was "disappointed" in the DEA's action.

"CVS/pharmacy is unwavering in its compliance with and support of the measures taken by federal and state law enforcement officials to prevent drug abuse and keep controlled substances out of the wrong hands," it said in an emailed statement.

The company said that that last fall, with the knowledge of the DEA, it had informed a small number of Florida physicians that it would no longer fill the prescriptions they write for controlled narcotics.

As a result, distributions of oxycodone to the two Florida stores that were raided have decreased by about 80 percent in the last three months from the prior three months.

Florida is at the epicenter of the national crisis of illegal prescription drug use. Seven people in the state die each day as a result of prescription drug abuse, more than from heroin, cocaine and methamphetamine combined, Trouville said.

Two other pharmacies were also served last week with suspension orders, but Trouville said they gave up their registrations rather than fight the matter in court. Under DEA rules, those pharmacies are not publicly identified.

CVS said it is cooperating with the DEA. In the meantime, "we remain committed to ensuring that all our customers, including customers of the two pharmacies, get the medications they need, including controlled substances."

Controlled substances are those, such as stimulants, painkillers and tranquilizers, that have the potential for addiction and abuse. Every entity that handles a controlled substance, from the manufacturer to the distributor to the pharmacy to the physician, must register with the agency.

Cardinal said on Friday that the DEA had suspended its license based on suspiciously high volume at the four pharmacies. But the company told a judge that it had already stopped shipping to two of the pharmacies several months ago, and stopped shipping to the CVS stores after its license was temporarily suspended on Friday morning.

Cardinal has protested the DEA's action, saying the agency fails to share information that could help industry and government alike prevent diversion of the products for illegal use.

Trouville declined to address Cardinal's concerns, saying, "That will be sorted out in court."

(Additional reporting by Jessica Wohl in Chicago; Editing by Lisa Von Ahn, Bernard Orr)

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