(AP) - An earthquake that struck eastern Tennessee early Wednesday could be felt as far away as Atlanta, the U.S. Geological Survey said.

The light earthquake occurred about 4:15 a.m., and was centered about 7 miles (about 10 kilometers) northeast of Decatur. About 15 minutes later, a 3.3 magnitude aftershock struck.

According to the USGS, the Eastern Tennessee seismic zone is one of the most active earthquake areas in the Southeast. The zone extends across parts of Tennessee, Georgia and Alabama.

There didn't appear to be any immediate reports of injuries, but people definitely felt it. Dispatchers said some people reported their beds shaking and dishes rattling.

The Tennessee Valley Authority said engineers were inspecting the Watts Bar Nuclear Plant in Tennessee as a precaution, but the facility didn't appear to be affected and was continuing to operate safely.

Meigs County Emergency Management Director Tony Finnell told the Chattanooga Times Free Press that there were no reports of damage but the county's 911 lines lit up as soon as it happened.

"We got a few calls because people woke up with noise and vibration," Finnell said.