(Reuters) - California's Napa Valley, the site of a strong and damaging earthquake a week ago, was shaken by a small aftershock early on Sunday.
The U.S. Geological Survey said the quake, measuring magnitude 3.2, occurred five miles southwest of Napa. There were no immediate reports of damage.
It was one of many aftershocks that have occurred since Aug. 24 when a magnitude 6.0 quake struck, the biggest to hit California's Bay Area in 25 years, injuring more than 200 people and damaging dozens of buildings.
Grape-harvesting season is getting under way in Napa County, where thousands of people are employed in wine production.
Reporting by Ellen Wulfhorst; Editing by Robin Pomeroy