Portage Police are investigating an armed robbery that occurred this morning at Steak n' Shake on U.S. Highway 6. Police say both suspects were wearing masks, with one displaying a knife and the other brandishing a handgun. Authorities report the incident took place after 4:30 this morning, and the suspects made off with an undisclosed amount of money. Police say a search of the area was unsuccessful, and that employees who arrived at nearby businesses did not observe anyone matching the suspects' description enter or leave the business. One suspect was described as standing five-foot-seven inches tall, wearing dark clothing, gloves, aviator-type glasses, and wearing what is believed to be a ski mask, while the other suspect was described as standing six-foot three inches tall, wearing dark clothing, gloves, aviator-type glasses, and some sort of mask to cover his face. No injuries were reported and no customers were inside the business at the time of the alleged incident. Anyone with information regarding this incident is asked to contact the Portage Police Department.