Federal agents have broken up a major international steroid smuggling ring operating in Denver's northern suburbs with six arrests and drug seizures carried out Wednesday.

Several people, including a tanning salon owner and two fitness center managers, were arrested in the raids, conducted under the code name Operation Adonis, said U.S. Attorney Mike Norton and Leslie G. Kinney, agent in charge of the U.S. Customs Service in Denver.Officials said they believe the ring operated for five years, bringing in $500,000 worth of steroids manufactured in Mexico for distribution throughout Colorado, Wyoming, Utah and Nebraska.

Those arrested appeared before U.S. Magistrate Richard B. Harvey late Wednesday on charges of smuggling, conspiracy, money laundering and violations of the U.S. Food and Drug Act, officials said.