An earthquake of 4.1 preliminary magnitude jolted parts of the southern U.S. on Saturday morning.

The quake hit about 13 miles from Greenback, Tennessee, which is about 30 miles south of Knoxville, the U.S. Geological Survey said, around 9 a.m. local time.

Residents in Atlanta and parts of western North Carolina reported on social media feeling the tremors.

The USGS initially reported the earthquake as a 3.5 magnitude quake before increasing it to 4.1.

There were no immediate reports of significant damage or injuries.

Gabriela Reilly was making waffles with her husband when they felt their entire home shake in Braselton, Georgia, which is northeast of Atlanta.

“Our ceiling fan started shaking for about 10 seconds,” she said. “I thought a giant aircraft had flown low right over the neighborhood, but my husband said, ‘No, that was definitely an earthquake!’”

Earthquakes are not uncommon in the region. The Eastern Tennessee seismic zone is one of the most active in the Southeast and extends across parts of Tennessee, Georgia and Alabama.

Two tremors struck in December 2018. One was a 4.4 magnitude earthquake that was centered in Decatur, Tennessee, which is south of Knoxville. It shook homes as far away as Atlanta.

Another earthquake struck a few days later with a magnitude of 3.0. Its epicenter was about two miles (four kilometers) southeast of Mascot, near Knoxville. It also was felt in parts of Georgia, Kentucky and North Carolina.