Massive scale persecution against the local Greek element started in 1961, as part of the "Eritme Programmi" operation that aimed at the elimination of Greek education and the enforcement of economic, psychological pressure and violence. Under these conditions the Turkish government approved the appropriation of the 90% of the cultivated areas of the island and the settlement of additional 6,000 ethnic Turks from mainland Turkey. The Turkish Government, also, closed the Greek schools on the island and classified it as "supervised zone", which meant that expatriates could not visit the island and their homes without special admission. Greeks on the island were also targeted by the construction of an open prison on the island that included inmates convicted of rape and murder, who were then allowed to roam freely on the island and harass locals. Some are said to have committed the same crimes before the prison was closed down in 1992. Farming land was expropriated for the prison. Furthermore, with the 1964 Law on Land Expropriation (No 6830) the farm property of the Greeks on the island was taken away from their owners.