PROVIDENCE, R.I. -- Providence police and Massachusetts State Police say they broke up a large-scale heroin and fentanyl trafficking operation that was funneling drugs from Greater Providence into Fall River and New Bedford, Mass.

In the last week, they arrested eight men and raided five houses in Providence, Central Falls and Pawtucket, and seized 2 kilos of heroin and fentanyl, with a street value estimated at $300,000. The police also collected suspected material from the drug operation -- six vehicles, $60,000 in cash and gold, including a 2.2 pound gold necklace.

The police called it Operation Grape Juice: “grape” for a house on Grape Street alleged to be a hub for the operation, and “juice” is slang for drugs.

Providence itself is a hub on the East Coast for drug trafficking, said some of the intelligence detectives who investigated the case. Large amounts of narcotics are brought into the city, and then distributed throughout New England at higher prices.

The Providence police intelligence and organized crime bureau began investigating this operation several months ago, said detective Maj. David Lapatin. The suspected traffickers, who are friends and relatives, were obtaining the narcotics in Providence and then moving them for distribution in the Providence area and into Fall River and New Bedford, he said. He declined to speak specifically about the investigation, which is ongoing.

The Massachusetts State Police Bristol County Narcotics Unit, and police from Pawtucket and Central Falls also worked with the investigators. Central Falls Police Col. James Mendonca said fentanyl is a pervasive, dangerous drug that’s affecting all walks of life, in cities and smaller communities. That’s why, he said, these investigations are so important.

“This was a major drug trafficking operation that was using Interstate 195 as the main source to funnel drugs from Providence to Fall River and New Bedford,” Providence Chief Hugh T. Clements Jr. said in a statement. “I commend Sergeant [Nicholas] Ludovici and his team, as well as our law enforcement partners, who worked tirelessly to ensure that these potentially lethal narcotics and criminals were taken off the streets. With the heroin and fentanyl epidemic continuing to be on the rise, the dismantling of drug trafficking organizations such as this one is crucial.”

Providence police charged Daniel Gonzalez-Ramos, 30, and Luis E. Romero Peguero, 24, with possession with intent to deliver one ounce to one kilogram of fentanyl and conspiracy. Pawtucket police lodged the same charges against Jose Moczo, 25, Adalberto Mercado, 30, Carlos Arroyo, 36, Alexander Arazena-Rosa, 38, Juan Ortega, 21, and Angel Vazquez, 41.

Police searched 31 Grape St., 142-144 Donelson St. and 27-29 Lisbon St. in Providence, as well as a residence in Central Falls and one in Pawtucket. Some of the vehicles they seized included a 2006 Honda Odyssey, a 2005 Honda Odyssey, a 2004 Subaru Outback, a 2005 Chrysler Pacifica, and a 2009 Acura MDX, all used by the men charged in the investigation.