Authorities say the suspect handed the clerk a note demanding prescription drugs at about 9:40 a.m. When the clerk alerted security, the suspect fled, with a large knife protruding from his waistband.
Officers responded to the scene but were unable to locate the suspect. No one was injured in the incident.
A suspect description was not immediately available. Anyone with information is urged to call Crime Stoppers at (800) 222-8477.