Two earthquakes, one with a magnitude 5.1 and the other of 3.9, struck northern Oklahoma on Saturday morning and were felt through much of the state but no damages were immediately reported, the U.S. Geological Survey (USGS) and local media said.
Both quakes were centered about 153 km northwest of Oklahoma City. The first quake hit at 11:07 local time (1707 GMT), and the second one came about 10 minutes later, the USGS said.
The larger earthquake was "probably the second-largest in Oklahoma and the largest in this general area," said John Bellini, a geophysicist at the USGS National Earthquake Information Center.
Mr. Bellini said Oklahoma's previous largest was a 5.6 earthquake in 2011. It was not known if Saturday's quake was related to oil production activities, he said.
The first quake was felt across central and northern Oklahoma, Tulsa's News On 6 television reported. The TV station said no injuries or damages had been reported.
Oklahoma has seen a surge in seismic activity in recent years, which seismologists have said may be linked to oil production activities.
