ROCKLAND – City police are investigating Tuesday night’s armed robbery of a Subway sandwich shop during which two gunmen made off with less than $1,000 in cash.

Deputy Police Chief Wallace Tower said the robbery occurred about 11 p.m., just as the clerk was cashing up for the night and preparing to close the store.

Tower said both of the men entered the shop wearing ski masks over their heads. One of the robbers brandished a handgun and demanded money. The clerk, who was alone in the shop, handed over “less than $1,000” in cash, and the two men then ran from the building, Tower said.

“She was frightened and visibly upset,” Tower said Wednesday of the clerk.

The Subway is in the Hannaford shopping plaza on Maverick Street. The clerk told police she saw the robbers run across Maverick Street toward the neighborhood around Pine Street.

Police responded immediately and combed the area in search of the suspects.

Maine State Police Trooper Steve Hills and his tracking dog, Ruger, worked the scene but were unable to pick up the robbers’ trail. Other troopers and deputies from the Knox County Sheriff’s Department also took part in the search.

Tower said Detective Sgt. James Pease was heading the investigation and that he and fellow investigators worked all night and much of Wednesday on the case.

The city’s last recorded robbery took place Feb. 1, 1997, at the Big Apple on Camden Street.