FAIRFIELD — An armed robbery attempt outside a local restaurant early Sunday, in which the assailant may have fired a gun, is under investigation.

The incident unfolded as two employees of Rio Bravo were leaving the restaurant, corner of Commerce Drive and Kings Highway, early Sunday. They flagged down an officer on his way to another call at the nearby Fairfield Metro Center.

The restaurant workers told the officer that they were confronted by a man standing outside a light blue Ford Mustang. Two more people were in the car, according to the report.

The man was holding a gun with both hands, the employees told the officer, and demanded all their money. The three employees fled back into the restaurant, and as they did, heard a loud noise, but were not sure if the sound was caused by a shot from a pellet gun.

The employees told the restaurant’s manager about the incident, and they all ran out the front door and across the street, where they flagged down the patrol officer.

They said the Mustang drove off, heading west on Kings Highway, about 40 seconds after they ran out of the restaurant.

No one was injured and no money was turned over to the assailant, police said.