(CBS) — Two men are charged with eight felonies, including armed robbery, after three employees at a Merrillville, Ind. Portillo’s were tied up and the restaurant safe was robbed of $3,500.

It happened about 11 p.m.

Merrillville Police Chief of Detectives Robert Wiley says two men showed up at the door to Portillo’s.

“They tricked their way into the building, posing as the cleaning crew.”

Wiley says the robbers were armed with one pistol and one stun gun. And he says they tied up the three workers.

“…With handcuffs and duct tape. They handcuffed the manager (and) got him to give up the safe combination.”

Detective Wiley says the robbers took about 35-hundred dollars from the safe – which was recovered.

Police caught the robbers on the scene – after two panic alarms were set off.

He says neither robber had worked at the Portillo’s, but he suspects they had “some information about the business from an employee-side.”