A magnitude-5.6 earthquake with an epicenter about 50 miles outside Oklahoma City hit around 10:53 p.m. CDT Saturday -- the largest quake in a series of nine to strike Oklahoma the same day -- the U.S. Geological Survey reported Sunday.

The largest earthquake of the day was a shallow 3.1 miles deep and centered four miles east of Sparks, the USGS reported.

NewsOK -- The Oklahoman's Web site -- described the quake as the largest ever reported in the state. And it was reportedly felt as far away as Arkansas, Illinois, Kansas, and Texas.

All the earthquakes Saturday were centered close to either Prague or Sparks, with magnitudes ranging from 2.7 to 5.6.