Bulgaria's parliament set up a special committee Wednesday to review shale gas exploration and production in an apparent bid by the government to relax a ban on the industry imposed in January.

The committee was tasked with "studying the good practices and legislative regulations in the exploration and production of natural resources without harming the environment," parliament said, giving the committee two months to come up with conclusions about the controversial hydraulic fracturing -- 'fracking' -- method used to release the gas.

The ruling right-wing GERB party, which proposed the creation of the committee, had earlier hinted it might review the shale gas ban, adopted hastily under a storm of public pressure in January.

"We'll have to change this ban as under it, we cannot even drill for conventional natural gas," Prime Minister Boyko Borisov told state BNT television last week.

None of the committee's members said Wednesday whether they would eventually propose a relaxation or lifting of the ban but they drew fierce criticism by the opposition Socialists, who said a lifting of the restrictions was the ultimate goal behind the committee's creation.

Bulgaria imposed the ban in January to justify revoking a five-year shale gas test-drilling permit granted last year to US oil giant Chevron.

The permit had drawn massive protests by environmental groups, who warned that the use of fracking to release shale gas risks contaminating land and drinking water, and triggering earthquakes.

Fracking uses high pressure injections of water, sand and chemicals to blast and crack rock to release oil and gas trapped inside.

Bulgaria, which is almost totally dependent on Russia for its natural gas needs, has been seeking ways to diversify its supplies by linking its gas network to those of neighbouring Romania, Turkey and Greece and studying possibilities to import liquified natural gas.

The country also backs both Russia's South Stream and EU's Nabucco pipeline projects to bring Russian and Caspian gas to Europe.