A large-scale investigation into major heroin and fentanyl trafficking operations in Essex County, Massachusetts, resulted in 12 arrests Friday night.

The arrests were part of a joint state and federal operation targeting heroin and fentanyl trafficking into Lawrence, Lowell, Haverhill and Peabody.

During the sweeping raids and warrants carried out by authorities on Friday, approximately 900 grams of suspected heroin and fentanyl was recovered from Haverhill and Lawrence, along with approximately $21,000 cash. Eight of the 12 suspects are charged with trafficking over 200 grams of heroin or fentanyl.

Attorney General Marua Healey called the arrests "the result of an extensive joint investigation into heroin and fentanyl targeting those who bring these lethal drugs into our communities."

Healey's office recently committed a $1 million grant from the Department of Justice to form a fentanyl strike force that aims to dismantle heroin and fentanyl tracking networks across Massachusetts.

The Massachusetts Department of Public Health estimates that 2,069 people died from opiod overdoses in the state in 2016. Essex County has one of the highest overdose rates in the state.