The arrests, which took place last week and were announced yesterday, "caused a serious disruption in the flow of powder and crack cocaine" into the county, according to a statement released by county Prosecutor Robert D. Bernardi.

Four of those arrested have alleged ties to the Bloods street gang, according to authorities, who said nearly $200,000 in drugs and assets, including a Mercedes-Benz sedan and an SUV, were seized.

The arrests capped a six-month investigation.

Authorities charged that Juan Martinez, 35, of Voorhees, was the prime supplier for the drug network.

Martinez and three others charged - Keypoe Dennis, 37, and Nathaniel Haggar, 24, both of Browns Mills, and Miguel Sanabria, 34, of Westampton - were identified as associates of the Bloods.

Martinez was arrested last week in the parking lot of a fast-food restaurant in Westampton, where authorities said he had gone to make a drug sale. At the time of his arrest, he was in possession of 27 grams of crack cocaine, $2,800 and three cell phones, authorities said.

A subsequent search of his home resulted in a seizure of 251 grams of cocaine, the two Mercedes vehicles, three flat-screen panel televisions, and a computer, authorities said.

Investigators also said 44 grams of crack cocaine, a digital scale, and packing material were found in the garage.

Martinez is held on $100,000 bail.

Others charged in the case include John Birch, 51, a mail carrier for the Postal Service. Birch was arrested at his home in Willingboro.

Authorities said that during the investigation Birch was observed buying cocaine in the parking lot of a discount store on Route 541. He was driving his Postal Service vehicle and wearing his uniform when the drug transaction took place, authorities alleged.

Another suspect, James Wright, 28, of Mount Holly, was arrested in the parking lot of a Marlton restaurant, where he had gone to complete a drug deal, they said. Police seized Wright's Lincoln Town Car and $10,800 in cash.

Others arrested were Mario Sanchez, 27, of Waterford Township; Saturnino Lebron, 30, Jennifer Rosenthal, 26, and Steven Skupejko, 39, all of Westampton; Kevin Arias, 29, of Eastampton; and Mark Cecelia, 45, of Burlington.

In addition to the 12 people arrested, authorities have issued a warrant for Charles J. Taylor, 36, of Browns Mills, in connection with the investigation.