Officials with the U.S. Geological Survey were advising Southern California residents Monday evening about a hoax letter that is warning of an "impending large quake."
The letter with the agency's logo was apparently being sent to residents in Orange County, urging them to be prepared for a large quake. "California is issuing a statewide warning," the letter states.
The agency advises residents to check the USGS website for the latest earthquake information.
The letter comes in the wake of Friday's 5.1 magnitude temblor centered in La Habra. The quake was felt across a large swath of Southern California. It caused modest damage to some homes, a rock slide in Carbon Canyon and broke some water mains.
An estimated 17 million people felt the quake, according to the USGS Did You Feel It? online reporting system.