Officers responded to Zales outlet diamond store at 8155 Camino Arroyo at around 8:55 p.m., where three men with handguns had entered the store in a "takeover" robbery, according to Gilroy police.
The men allegedly threatened store employees, though no one was reported injured.
The suspects stole an undisclosed amount of jewelry and drove off in a light-colored sedan.
Police have not yet identified possible suspects. An investigation is under way. Anyone with information is asked to contact Gilroy police Detective Stanley Devlin at (408) 846-0350. Anonymous tips can be made by calling (408) 846-0330, the We Tip line at (800) 782-7463, or (800) 78-CRIME.