Police say two men began smashing display cabinets at La Swiss Watch City at about 5:15 p.m. PT.
While the suspects grabbed merchandise, one man held staff at gun point.
The suspects fled the scene on foot and unleashed bear spray as they ran off.
Investigators say two mall customers were taken to hospital after inhaling bear spray.
The two suspects are described as white men in their 40s, about five feet eight inches tall with medium builds. Both were wearing black hoodies with the hoods up and black pants.