MIAMI (AP) _ The FBI confirmed Friday it has joined an investigation of Miami-area police departments following charges that officers engaged in drug-related armed robberies, stole department money and sold police equipment to criminals.

''We are currently conducting an active investigation ... of police corruption,'' said a statement issued by the FBI's Miami office. ''We have no further comment to make.''

At least three major area police departments have suffered scandals in recent weeks.

Worst hit has been the city of Miami. One active and one retired officer were arrested Aug. 29 and charged with selling police weapons, as well as offering police badges and radios, to undercover investigators posing as armed ''home invaders.''

Law enforcement sources told The Associated Press that the FBI and other agencies are investigating criminal activity by as many as 10 other officers in the Miami police department, at least some involving home invasions.

Included in the investigation is a triple murder of suspected drug dealers, according to The Miami Herald.

A rash of home-invasion robberies, in which criminals break into houses, tie up or beat the occupants and steal cash and often drugs, has plagued the Miami area this year.

Home invaders often target suspected drug dealers, hoping to recover large amounts of cash or find drugs than can be sold, said Lew Wilson, assistant chief of the southern region of the Florida Department of Law Enforcement.

He said his agency is ''deeply involved'' in investigating charges of police links to robberies and drug-related corruption.

Last week $150,000 intended for use by undercover agents was stolen from the Miami police narcotics unit safe. Two officers have been relieved of duties in the unit, but no criminal charges have been filed.

The Metro-Dade police department, which patrols the populous unincorporated area around Miami and other Dade County municipalities, last week arrested one of its own officers, Miguel Vidal, 25, and charged him with a home invasion armed robbery, kidnapping, and attempted first-degree murder.

In Hialeah, which borders Miami and is the state's fifth largest city, Mayor Raul Martinez on Thursday fired Carlos Simon, 27, a police officer found innocent of murder in a home-invasion robbery. Martinez said the firing was based on evidence not allowed in the courtroom.

Published reports say a dozen Hialeah officers are also under investigation. Martinez refused Friday to confirm details of the investigation, but said he has set up a panel of four lieutenants to examine recurrent charges of corruption and crime in his department.