The following years, measures were taken to suppress the minority's education. The Albanian state viewed Greek education as a potential threat to its territorial integrity, while most of the teaching staff was considered suspicious and in favour for the Northern Epirus movement. In October 1921, the Albanian government recognised minority rights and legalised Greek schools only in Greek speaking settlements located within the "recognised minority zone". Within the rest of the country, Greek schools were either closed or forcibly converted to Albanian schools and teachers were expelled from the country. During the mid 1920s, attempts at opening Greek schools and teacher training colleges in urban areas with sizable Greek populations were met with difficulties which resulted in an absence of urban Greek schools in coming years. With the intervention of the League of Nations in 1935, a limited number of schools, and only of those inside the officially recognized zone, were reopened. The 360 schools of the pre-World War I period were reduced dramatically in the following years and education in Greek was finally eliminated altogether in 1935: