Jerusalem ( CNN ) -- Some 100,000 ultra-Orthodox Jews protested Thursday an Israeli Supreme Court decision banning segregation based on ethnic background in a girls ' religious elementary school . Girls of Sephardic origin were being denied permission to share classrooms with the largely Ashkenazi school and were forced into segregated classes . Sephardic Jews are of North African and Middle East origin , Ashkenazim are Jews of European background . The ultra-Orthodox community in Israel is made up of many sectors reflecting many different traditions . The demonstrators resent what they feel is the intervention of the Israeli state into religious affairs . The school is Beit Yaakov in the West Bank settlement of Immanuel . Large demonstrations were held in Jerusalem and Bnei Brak near Tel Aviv . Police said 100,000 protesters demonstrated in Jerusalem , including 20,000 who joined the gathering from Bnei Brak . In response to a petition the court ruled that this was a case of discrimination . It ordered the school to integrate all the pupils . But 43 sets of parents who refuse the court order were to be incarcerated for two weeks on charges of contempt of court on Thursday . The parents of the school girls in question deny that their opposition to integrating Sephardic girls is based on ethnicity , but insist that it is about their religious observance which they believe is stricter than the families of those being refused . One protester Yehoshua Friedberg , told CNN , `` We see this as the right that parents have to allow their children to receive the education they believe in . '' The mood among the thousands of demonstrators in their traditional black-clad garb was one of defiance . A young student proclaimed `` we go to jail because the judge told us to do things against the Torah ( Bible ) . Our rabbis and we will go to jail until the end . ''
NEW : Around 100,000 demonstrate . Tumult reflects state-religion tensions in Israel . Ruling casts light on Ashkenazi , Sephardic tensions .