Corporal Ian Alexander of the Sagadahoc County Sheriff’s Office follows Rocko the drug-sniffing dog around the perimeter of Lisbon High School on Thursday morning during a drug sweep. The exercise is an annual event.

LISBON — Authorities used drug-sniffing dogs during a sweep of Lisbon High School Thursday morning. The dogs checked areas inside and outside the school, local police Detective Bernie McAllister said. School officials invited police to perform the sweep, he said. The request usually comes about once a year.

McAllister declined to comment on whether any contraband was found. Included in the sweep were canine officers from Bath Police Department, Sagadahoc County Sheriff’s Department, Cumberland County Sheriff’s Department and Lisbon Police Department. Also on scene were a local sergeant, a detective and two school resource officers.