Five earthquakes were felt by residents of Mahoning County in northeastern Ohio on Monday and Tuesday, bringing the total number of area earthquakes in the past several days to 11, local paper the Tribune Chronicle reports.
The U.S. Geological Survey pinpointed the epicenters of some of these quakes to be in the vicinity of seven oil and gas production wells in Poland Township, Ohio, that are owned by Houston-based company Hilcorp Energy, according to the Business Journal Daily.
On Monday afternoon, the Ohio Natural Resource Department ordered Hilcorp Energy to cease drilling operations so that state officials can take a closer look at whether the energy company could be triggering the quakes.
"ODNR is using all available resources to determine the exact circumstances surrounding this event and will take the appropriate actions necessary to protect public health and safety," a representative for the department told The Huffington Post in an email. However, the agency added that available information indicates the quakes were not connected to Hilcorp's operations.
Still, some think there could be a link between the fracking and the seismic activity.
"Not only were the earthquakes nearby the [drilling] site, but the depth of the earthquakes is consistent with where the drilling was happening," Alison Auciello, organizer for the nonprofit organization Food and Water Watch Ohio, told HuffPost.
Auciello pointed out that other fracking operations have been connected to earthquakes in Ohio before. In early 2012, the state permanently shut down a disposal well -- where fracking wastewater is injected into the ground -- in nearby Youngstown after the well was linked to a series of earthquakes that occurred in the area in previous years.
It's important to note, however, that Hilcorp says it has no disposal wells -- only production wells -- in the area of the recent earthquakes, so the comparison to what happened in Youngstown should be taken with a grain of salt.
"We welcome the inquiry into exactly what happened," Hilcorp said in an emailed statement to HuffPost. "[We] encourage state inspectors to provide the community with as much information as possible."
Hilcorp, however, also said it was too early to know whether there was any connection between its drilling and the tremors. A representative added that the company had drilled a number of wells in Ohio recently without incident.