HAMMOND | Thirteen people from Hammond and Dyer face charges following a drug sting Wednesday that netted 17 kilograms -- about 37 pounds -- of powder cocaine during a traffic stop in Porter County, federal court records state.

A lengthy affidavit describes an operation that was moving between 10 and 15 kilograms of cocaine and 25 to 30 pounds of marijuana per week. The drugs allegedly were purchased in Mexico and stored in a warehouse in Chicago.

Charged in the case were defendants Blas Robles Sr., Blas Robles Jr., Jose Manuel Robles, George Leber, Santiago Gutierrez, Cory King, Jesus Cahue, Juana Mariana Robles, Andres "Chi Chi" Zaragoza, Ysidra Robles, Clarence Johnson, Saul Galvan and Ismael Ruvalcaba.

Each faces charges of conspiring to distribute more than five kilograms of cocaine and 100 kilograms of marijuana. Their initial court appearances with Assistant U.S. Attorney David Nozick lasted several hours Wednesday afternoon and are expected to continue today.

On Jan. 30, Zaragoza and Cahue were pulled over by Indiana State Police on Interstate 80/90 in a van that had packages cocaine hidden in a compartment in the back, court records allege. The van was impounded, and authorities subsequently discovered the drugs.

The operation was the result of a joint investigation between the FBI, the federal Gang Response Investigative Team, the Bureau of Alcohol, Tobacco, and Firearms, the Indiana State Police and the Hammond Police Department, FBI spokeswoman Wendy Osborne said.

Hammond Police Chief Brian Miller said he was proud of how smoothly the various agencies worked together on the joint operation.

"It was the culmination of a group investigation," Miller said. "It was a very successful venture. The arrests were made (Tuesday) night without incident. No one was hurt."