An earthquake has rattled parts of northern Oklahoma and southern Kansas.
The U.S. Geological Survey reports the magnitude-4.3 quake struck about 9 miles southeast of Medford, Oklahoma, on Thursday night. Initially the quake was rated 3.9, but later upgraded to a 4.3.
No injuries or damage was immediately reported. Medford is more than 90 miles north of Oklahoma City.
A smaller 2.5-magnitude earthquake was recorded around 5 p.m. Thursday roughly 10 miles west of Harper, Kansas.
Thousands of earthquakes have been recorded in Oklahoma in recent years. Many of them have been 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.