Four small earthquakes have been recorded across northern Oklahoma by the U.S. Geological Survey.
No injuries or damage are reported.
The strongest quakes were magnitude 3.1 and magnitude 3.0, both recorded about 5:30 p.m. Friday near Covington, about 55 miles north of Oklahoma City.
A 2.7 magnitude quake was recorded at 6:34 a.m. Saturday near Hunter, 80 miles north of Oklahoma City and a 2.5 magnitude quake struck at 12:33 a.m. Saturday near Aline, 89 miles northwest of Oklahoma City.
Thousands of earthquakes have been recorded in Oklahoma in recent years, with many linked to the underground injection of wastewater from oil and natural gas production operations.
State regulators have directed oil and gas producers to close some wells and reduce injection volumes in others.