Oklahoma was hit by seven minor earthquakes in less than 24 hours over the weekend.

The quakes, recorded in central Oklahoma by the U.S. Geological Survey over about 14 hours, have renewed speculation that hydraulic fracturing -- a controversial oil and gas drilling practice also known as fracking -- is behind the increase in seismic activity in the area.

The first quakes struck Saturday and ranged in magnitude from 2.9 to 3.2. A 4.3-magnitude temblor near Langston also was recorded Saturday afternoon, The Associated Press reported.

"Sunday's quakes 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 AP reported. Fortunately, no injuries or damage was reported.

Last month, Oklahoma beat California to become the state with the most earthquakes. As of June 16, "California had recorded about 140 quakes" with at least a 3.0 magnitude, while Oklahoma had had 207, CNN reported.

"The rate of earthquakes in Oklahoma has increased by about 50 percent since October 2013," states the U.S. Geological Survey, which is researching the cause behind the drastic increase.

"Earthquakes are going to be a normal part of everyday life in Oklahoma," CNN meteorologist Chad Myers said. "They are going to become more and more a part of life there."

Many people believe fracking, which involves drilling into deep layers of rock and injecting treated wastewater between the layers to extract oil and natural gas, caused the quakes. They say the wastewater injection is causing the ground to shift, KFOR reported.

However, fracking is crucial to the state's economy, since one of every six workers in Oklahoma depends on the oil and gas industry for employment. Plus, the industry produces almost 30 percent of the state's annual tax revenue.

Scientists have not confirmed whether or not fracking is behind all or any of the recent earthquakes in Oklahoma.