Lebanon police are investigating robberies at three businesses since Monday.
City police said the first incident occurred Monday evening at the Family Dollar at 306 Cumberland Street, where a man in the checkout line put his hand in his coat pocket and said "Give me your money, I'm serious."
The clerk believed the man was armed and gave him an undetermined amount of cash, police said.
On Tuesday night, an employee of Domino's Pizza at 1303 Cumberland Street reported that a man displayed what appeared to be a handgun and demanded money.
The employee said the robber had a black mask over the bottom of his face and was also wearing black gloves, according to police.
Early Wednesday, a clerk at the Turkey Hill at 716 East Lehman Street told officers a robber displayed a knife and demanded money.
No one was injured in any of the incidents.
Anyone with information may call Lebanon police at 717-272-6611.