After a yearlong investigation, an early morning raid has left many southwestern Connecticut drug suspects behind bars, federal authorities say.

The investigation included the DEA and state police, as well as officers from local departments including Bridgeport, Milford and Fairfield. The state prosecutor says they executed more than 20 search warrants Wednesday morning, all involving a heroine trafficking operation that started in Milford.

Police were able to seize drugs, firearms and money in the morning sweep while placing as many as 50 suspects under arrest. The state prosecutor says the suspects will be arraigned Friday while more arrests should be made over the next several days.