No damage or injuries were reported after a 3.9 magnitude earthquake struck northern Oklahoma early Monday. The earthquake was recorded at 2:15 a.m. about 10 miles southwest of Medford and 21 miles north of Enid. The quake was about 4.8 miles deep. It was felt in portions of Oklahoma, and Kansas.

Monday’s earthquake follows a series of temblors that rattled Oklahoma over the weekend. The U.S. Geological Survey recorded seven small earthquakes shaking central Oklahoma in a span of just about 14 hours.

They ranged from magnitude 2.6 to 2.9 and were centered in the Guthrie, Jones and Langston areas, 15 miles to 30 miles northeast of Oklahoma City. The USGS said the quakes were recorded between 7:57 p.m. Saturday and 9:51 a.m. Sunday. No injuries or damage were reported.

Those follow four other quakes, including a 4.3-magnitude temblor near Langston recorded shortly after noon Saturday. The other Saturday morning quakes ranged in magnitude from 2.9 to 3.2.

The Oklahoma Geological Survey has said the state is experiencing unprecedented earthquake activity and that his agency is closely monitoring it to determine whether the quakes are a natural phenomenon or are man-made.