WISCASSET – A bus bound for a Portland methadone clinic was stopped by police Wednesday morning at a Route 1 convenience store for an alleged drug transaction between two riders.

The stop resulted in the arrest of a Rockland woman.

The alleged incident occurred while the bus was traveling through Edgecomb, but the bus was met by Lincoln County Sheriff’s Criminal Investigation Division and Wiscasset police at an Irving Maineway convenience store around 8 a.m.

Detective Kenneth Hatch was the lead investigator.

After questioning a male and female who were passengers on the Coastal Trans bus, the woman was arrested and the man summoned on a drug charge, sheriff’s spokesman Greg Latimer said Wednesday.

Sharmon Elizabeth Clark, 42, of Rockland was arrested on a charge of furnishing scheduled drugs (Clonazepam). She appeared Wednesday afternoon in District Court, Latimer said, and pleaded guilty to the charge. She was fined $375, he said, noting seven pills were found in her possession.

Chris Masden, 27, of Damariscotta was summoned for unlawful possession of scheduled drugs. When searched, police found four Valium pills and three Clonazepam pills in his possession. No information on his court date was available.

According to Latimer, all of the passengers were headed to the methadone clinic.

Wiscasset police Chief Michael Emmons said about a dozen passengers were on board when the vehicle was stopped at the Irving Mainway property.