With the support of Buddhist nationalists, the SLFP introduced and eventually passed the divisive Sinhala Only Act, which made Sinhala the only official language of the nation. This alienated many minorities like the Sri Lankan Tamils in the process, who sought regional autonomy. Under Sirimavo Bandaranaike (the world's first female prime minister), the Freedom Party also nationalised most schools in the country that received government aid (a few Catholic schools were fully privatized to avoid this fate). This was particularly resisted by the Catholic minority who ran a widespread system of mission schools (which was considered by the Buddhist nationalists as part of the legacy of colonialism).