Am I still obligated to wear hijab at school when the school forbids it?

As a Muslim girl I know that wearing a hijab (scarf for covering the hair) is compulsory and I do wear it. But wearing the hijab isn't permitted in the school where I study. They also don't allow other students to use things that would reflect their religion, like a Hindu student is not allowed to use a Bindi on his/her forehead. They say that this promotes equality among the students. Now I am confused what to do. Is it acceptable not to wear hijab at school in this situation?