Well, Sergey has a point.
The parent(s) did wrong in the eyes of a religious faction. The children of the parent(s) get ' punished' through expulsion. Basic human rights - everyone has the right to free will, education, religion.
The school may have (as I believe it is a private school) rules regarding conduct but the children aren't in any way at fault apart from if they perhaps voiced their parent (s) opinion(s) at the school.
Bottom line is though that the children have been expelled thus making it look like the children have been punished for what their parent(s) did and this is plain wrong!!