They say the protests were triggered by the mounting of pylons for a chair lift to the famous Rila Lake area and the Environment Minister's refusal to interfere.
The organizers claim that the skiing resort, part of which is the chair lift, trespasses the border of the Rila National Park in violation of Bulgarian and European laws.
The Saturday protests were organized in the capital Sofia, in Varna on the Black Sea, in Plovdiv, Pazardjik and Kazanluk in the south, and Silistra, Shoumen and Veliko Turnovo in the north.
Citizens for Rila is based in Silistra. In this Danubian town, more than 500 signed a petition against the illegal construction. Their signatures are added to over 100,000 which have already been collected in the Rila campaign. At the end of March the petition will be presented to the European Parliament.