The latest men to be charged were arrested over the so-called "sledgehammer" plot, which reportedly dates back to 2003. Reports of the alleged plot first surfaced in the liberal Taraf newspaper, which said it had discovered documents detailing plans to bomb two Istanbul mosques and provoke Greece into shooting down a Turkish plane over the Aegean Sea. The army has said the scenarios were discussed but only as part of a planning exercise at a military seminar. The alleged plot is similar, and possibly linked, to the reported Ergenekon conspiracy, in which military figures and staunch secularists allegedly planned to foment unrest, leading to a coup.