Romania's prime minister on Wednesday said the government should not be "influenced" by anti-shale gas campaigns as plans to allow US company Chevron to explore for the resource has sparked protests.

The method to extract shale gas is controversial with environmentalists saying it poses serious threats that include contaminating ground water and triggering earthquakes.

Cited by news agency Mediafax during a meeting, Victor Ponta told Environment Minister Rovana Plumb that Romania needs to "continue on the right path already taken by the United States and some European countries, that of exploring for new sources of energy".

Ponta said the path consisted of "respecting environmental rules, correctly informing the population, but without letting ourselves be influenced by campaigns" against the exploration of these energy sources.

The technique to extract the gas, hydraulic fraction or fracking, has been banned in countries such as France and Bulgaria but is widely used in some US states.

Fracking is a process whereby liquid products, including water and chemicals, are pumped deep into oil or gas-bearing rock to cause fractures and release the hydrocarbons.

Romania, together with Britain, Hungary, Poland and Spain strongly pleaded for developing shale energy during the last European council on energy.

Ponta, in power since May 2012, had slammed the previous government's decision to grant Chevron and other oil groups concessions to prospect for shale gas.

His government last year adopted a moratorium on drilling, putting Chevron's operations on hold.

But since the moratorium expired in December, Ponta has said he was in favour of exploration.

On Monday, thousands of Romanians protested against the plans, accusing Ponta of flip-flopping on his position against shale gas.