The only company in the UK with hydraulic fracturing to release natural gas from shale rock, said Wednesday that the controversial technique was probably trigger earth tremors in April and May.
However, a report commissioned by the Gang of Resources, which is the extraction of gas in the northwestern city outside the English seaside resort of Blackpool, noted that the tremor, measuring 1.9 and 2.8 at the Richter scale - was due to an unusual combination of geology and operations and is unlikely to happen again.
Gang is the only company currently extracting shale gas fracturing - a controversial technique which is pumped by a mixture of water, sand and chemicals inside underground rock formations to release gas.
Fracturing operations were suspended on May 27 after detection of an earthquake centered in the outskirts of Blackpool.
The company said that operations remain suspended, while the company and government officials consider the report.
The use of the fracture, colloquially known as "fracking," has increased dramatically in recent years, particularly in the United States, and residents and environmental activists have expressed concern about the potential impact on water quality.
Critics say fracking could poison water supplies, while the natural gas industry says it has been used safely for decades.
Nick Molho, the environmental charity WWF said on Wednesday that the findings can contribute to the "very real concern" people had about fracking.
However, the report estimates that in the "likely scenario" which fracking started another earthquake, the maximum size would be about 3 - which means it is likely that he was barely if at all.
Meanwhile, activists who oppose fracking pounced on one of the platforms of the company in a protest against the industry.
In a statement, said he believed the crew had "five protesters at the site, four of which are attached to the machine."