The U.S. Geological Survey is reporting a 3.9 magnitude earthquake has struck northern Oklahoma. There were no immediate reports of injuries or property damage.
The USGS says the epicenter of the earthquake Sunday night was about 9 miles east of Pawnee. The quake was as far north as the southern Kansas border and as far south as Oklahoma City.
Another quake, measured at 3.6, was recorded about 3 a.m. this morning near Cushing.
Oklahoma's earthquakes have been linked to oil and gas production, and state regulators have shut down or imposed new restrictions on underground wells that are used for wastewater disposal.