ELKHART, Ind. (AP): Two more parents have joined a federal lawsuit challenging a northern Indiana school district using a live Nativity scene as part of its annual Christmas show.

The Elkhart Truth reports the two parents of Concord High School students are seeking to remain anonymous because they are worried about what will happen if their names become public. The father and son that originally filed the lawsuit were allowed to stay anonymous after a judge decided there was a risk of violence.

The Freedom From Religion Foundation and the American Civil Liberties Union sued the district, arguing that a Nativity scene conveyed an endorsement of religion. The district in December used mannequins instead of student actors.

The case may not go to trial until next year.