WOBURN, Mass. (AP) — Authorities say they have arrested eight Lowell residents allegedly involved in an illegal gun sales operation.

Middlesex District Attorney Marian Ryan and Lowell Police Superintendent William Taylor said Wednesday the investigation involved the execution of more than a dozen search warrants and resulted in the seizure of three shotguns, including an illegally modified sawed-off shotgun, two rifles, a revolver and two semi-automatic handguns.

State and federal agencies helped.

Investigators also seized heroin, cocaine, prescription pills and more than $11,000 in cash and rare coins.

The eight suspects were arraigned on a variety of firearms and drug charges. One was held on $550,000 bail.