According to SofiaEcho.com, the Bulgarian edition of the Sonisphere festival has been officially cancelled"Due to reasons outside Balkan Entertainment's control and at the instruction of the license-holder for Sonisphere in Bulgaria, the Sonisphere Bulgaria 2011 festival, planned for June 21, 2011 at the National Hippodrome in Bankya, is cancelled," promoters Balkan Entertainment said in a statement. On June 9 one of Sonisphere Bulgaria's two headliners, SLIPKNOT, said that the promoters cancelled the show, an allegation that Balkan Entertainment denied. SLIPKNOT then announced a special headline show at Columbiahalle in Berlin on the same date when Sonisphere Bulgaria was to be held, June 21. Balkan Entertainment's Petar Petrov told Z-Rock radio station that the promoters were unpleasantly surprised by the news and that the company did not cancel SLIPKNOT's gig. Read more from SofiaEcho.com.