WASHINGTON -- Authorities say they have shattered Internet drug rings that illegally peddled pharmaceuticals to tens of thousands of people worldwide every month, using the Web as a drug pipeline for teenagers and abusers.

Officials announced the arrest of 20 people in eight U.S. cities and at least two other countries, India and Costa Rica, in the last two days and described the operation as a major blow to rogue online pharmacies. Among organizations targeted was an Internet pharmacy based in Philadelphia that allegedly smuggled prescription painkillers, steroids and amphetamines into the United States from India, Germany, Hungary and elsewhere, repackaged them and sold them throughout the world.

"We've logged off some of the worst e-traffickers out there," Drug Enforcement Administrator Karen Tandy said Wednesday.

Even so, Tandy said the shadowy world of online sales of narcotics, amphetamines and depressants has been exploding. Unethical operators make little or no effort to verify the medical needs or ages of buyers.

"Today is every parent's nightmare," Tandy said. "The Internet has become an open medicine cabinet. Strangers are peddling drugs in your home, and you don't even know it."

"There is no visit to a doctor, no pharmacist to vouch for the integrity of the medication and no prescription," U.S. Attorney Patrick Meehan said at a news conference in Philadelphia to discuss the indictment in the case there. "All you need is a keyboard and a credit card, and you're able to order drugs like codeine, ketamine (a popular club drug) and steroids."

The indictment charged that Brij Bansal, a physician in Agar, India, headed the organization with his children, including 26-year-old son Akhil Bansal, a graduate student at Temple University in Philadelphia, the indictment charged.

Their organization filled orders for millions of pills placed by more than 4,500 buyers, many of whom sold the drugs in turn through at least 20 Web sites or on the streets, officials said.

An Airborne Express supervisor in suburban Philadelphia prompted the investigation when he found courier envelopes full of diazepam, a generic form of Valium, in packages being shipped by a local business that sent more than 4,300 packages in a 19-day period in February 2004, officials said.

The Bansals allegedly obtained the drugs in India and sent them to the United States, where they were redistributed. Authorities still are trying to determine where the drugs were manufactured, but Meehan said many probably were made by legitimate pharmaceutical companies.

Five members of the Bansal family have been charged, along with at least five Web site operators.

Drugs meant to aid sexual dysfunction were among the most popular in the scheme, Meehan said.

This was part of a yearlong investigation that led to the arrests by six federal agencies at online pharmacies.

Tandy and officials from the FBI, Immigration and Customs Enforcement, the Internal Revenue Service, Food and Drug Administration and the U.S. Postal Service gave details of Operation Cyber Chase at a news conference outside Washington. Officials said they are seeking forfeiture of 41 bank accounts in the arrests, and the illicit sales amounted to more than $6 million.

U.S. arrests took place in Fort Lauderdale and Sarasota, Fla.; Abilene and Tyler, Texas; New York City and Rochester, New York; Philadelphia; and Greenville, S.C. Authorities also made arrests in Costa Rica and India.

Tandy said the arrests represent only "the tip of the iceberg" in terms of how many illegal pharmaceutical groups are passing drugs over the Internet.

Legitimate sellers require customers to send in doctors' prescriptions before they will ship.