Residents of Bulgaria's Black Sea capital Varna staged Sunday a protest rally against shale gas exploration and production in the country.

The demonstrators demanded a moratorium on the hydraulic breaking technology and legislative amendments banning the use of harmful substances in the search and extraction of shale gas.

The issue of shale gas drilling in Bulgaria on concession by the US energy giant Chevron Corp escalated in the past few weeks, with environmentalists staging several protests and voicing concerns that two shale gas wells were being prepared for a launch.

Energy Minister Traicho Traikov refuted the claims, saying that the platform in the northeastern village of Rogozina was used for conventional drilling.

The protesters also drew attention to the fact that Environment Minister Nona Karadzhova, who recently claimed that all anti-shale gas rallies had been attended "the very same 5 perople" pretending to represent civil society in Bulgaria, had failed to ensure the mandatory Natura 2000 impact assessment for certain gas wells.

On November 23, the Bulgarian Socialist Party (BSP) tabled in Parliament a draft bill envisaging a ban on shale gas exploration and production in the country.

BSP's step came in response to Prime Minister Boyko Borisov's November 18 invitation to parliamentary opponents of shale gas to table a petition for a ban and to carry the responsibility for their decision.

One day earlier, the marginal conservative party Order, Law and Justice (RZS) submitted to Parliament a draft decision proposing a ban on shale gas drilling while the Bulgarian nationalist Ataka party proposed in the Parliament to debate a moratorium on the issue, but the MPs rejected the proposal.

The proposals must be debated by the Economic Policy, Energy and Tourism and the Environment and Waters Committees. The scheduled date was November 30, but the Ministry of Economy, Energy and Tourism failed to submit the needed report and to send a representative to the meeting, which got postponed for next week.