Italy's Emilia-Romagna region on Tuesday suspended new drilling as it published a report that warned that hydrocarbon exploitation may have acted as a "trigger" in twin earthquakes that killed 26 people in 2012.
The scientific report was commissioned after the quakes amid popular anger over alleged links to drilling activities, particularly an oil field, a gas storage facility and a geothermal energy plant in the area.
The report said that activity at the Mirandola oil fields "may have contributed to trigger the Emilia seismic activity" although it did not "induce" it.
It found that the last previous tremor in the region and the first quake on May 20 were "statistically correlated with an increase of extraction and injection activity" at one of the Mirandola fields.
Extraction and injection "may have contributed, adding a minute additional load, to the activation of a pre-stressed fault system already close to the conditions required to produce a significant earthquake," it said.
The report was authored by an international committee of scientists led by Peter Styles, a professor of applied geophysics at Keele University in Britain.
It recommended further studies, a system of evaluation for any new hydrocarbon or geothermal exploration activities and more monitoring for existing ones.
It also said that an "operational traffic light system" should be created to warn any drilling facilities about rising stress levels in the faults.
Based on the report, local authorities in Emilia-Romagna said they were extending a ban on drilling activities in the earthquake area to the entire region.
"All new exploitation will be banned in the region until new data are gathered," said Paola Gazzolo, a regional official in charge of land issues.
Small tremors in Britain, Canada and the United States have been linked to the practice of hydraulic fracturing or "fracking" for hydrocarbon extraction, although none has proved fatal.
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