PITTSBURGH (AP) – Authorities say they’ve broken up a $4 million cocaine ring that had operations stretching from Dallas to Atlanta to Pittsburgh.

Pennsylvania Attorney General Tom Corbett says a grand jury recommended the charges filed Tuesday against 21 people as part of a drug ring that used Greyhound buses to ferry cocaine into western Pennsylvania.

Prosecutors say a drug distributor in Atlanta sent the drugs to the Pittsburgh area then took proceeds back, sometimes through Dallas.

Agents estimate that between 20 and 40 kilograms of cocaine were being transported into the area every month from at least 2008 until August. Authorities say investigators purchased more than 400 grams of cocaine 11 controlled buys this year.

Corbett says he anticipates more arrests.

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