Parallel protests are planned for Wednesday in Bulgaria and Romania against the environmentally hazardous technique of drilling for shale gas known as hydraulic fracturing.

Environmentalists and ordinary citizens have chosen June 5, World Environment Day, to express their vehement opposition to plans by the Romanian government to allow the start of shale gas exploration by US energy giant Chevron.

Rallies are planned in the two capitals, Sofia and Bucharest, while road marches on both sides of the border are set to meet at the Durankulak - Vama Veche crossing point.

Rallies will also be held in Cluj, Sibiu, Mangalia, Iasi, Sigisoara and Brasov in Romania, as well as in Varna and Dobrich in Bulgaria.

The areas that Chevron plans to explore for shale gas are all in the Dobrudzha (Dobrogea) area shared by the two countries, with one of them near Vama Veche, right at the Bulgarian border.

Dobrudzha is among the most fertile and agriculturally used areas by both Romania and Bulgaria, and shale gas fracking is known to pose special hazards for the pollution of ground waters with little known chemicals and gas.

Chevron had also expressed interest to drill for shale gas in the Bulgarian section of Dobrudzha, but early 2012 parliament passed a moratorium banning all shale gas exploration and production in the country.

Bulgarian organizers of the protests have said that they both wish to show solidarity with their neighbors, and to prevent pollution in Bulgaria from shale gas development in Romania.

Protesters on both sides of the borders have vowed to lead a global fight against shale fracking set to ultimately ban the technique worldwide.

In addition, Bulgarian organizers have been alarmed by a statement from new Environment Minister Iskra Mihaylova, hinting that she might be willing to lift the moratorium.