The U.S. Geological Survey says a 4.3-magnitude quake struck at 9:06 a.m., centered about six miles east of Norman. The National Earthquake Information Center had measured a preliminary magnitude of 4.5 and said it was felt as far away as Wichita, Kan.
Authorities reported two people taken to a Norman hospital with minor injuries, including a man who fell off a ladder.
Some minor damage such as broken windows also was reported.
Norman police Capt. Leonard Judy says the quake sent officers running out of the department to see if someone had crashed into the building.