A series of low-intensity temblors were reported from Texas on Tuesday and early Wednesday with the strongest measuring 3.6 on the Richter scale, according to media reports. However, no major damage or injuries have so far been reported.

While the first earthquake was felt at 7.30 a.m. on Tuesday, the most recent one was felt at around 1 a.m. on Wednesday morning, according to media reports. The earthquakes were clustered around the Dallas suburb of Irving, which has reportedly experienced over 20 minor earthquakes since September last year.

Jana Pursley, a geophysicist at the U.S. Geological Service (USGS), said that the latest quakes were “the largest since the earthquakes started happening there in the last year,” according to media reports.

According to Reuters, several residents of the region have speculated that the increase in the frequency of earthquakes may be related to hydraulic fracturing, or fracking, activity, which involves exploding shale rocks to create fissures for the extraction of trapped natural gas.

Irving is the headquarters of Exxon Mobil, which has helped pioneer hydraulic fracturing in the region. The city also has two gas wells that were fracked in 2010, according to media reports.

“There is evidence that some central and eastern North America earthquakes have been triggered or caused by human activities that have altered the stress conditions in earth's crust sufficiently to induce faulting,” USGS said, in a statement. “Activities that have induced felt earthquakes in some geologic environments have included impoundment of water behind dams, injection of fluid into the earth's crust, extraction of fluid or gas, and removal of rock in mining or quarrying operations.”

However, USGS added that the link between human activities and increase in the frequency of earthquakes in the region was not conclusive and that further “special studies devoted specifically to the question” were required to study the connection between the two.