Harvard University is asking judges to dismiss a pair of lawsuits challenging a school policy that discourages students from joining single-gender clubs.

Court documents filed by Harvard on Friday deny allegations of sex discrimination made in separate lawsuits in state and federal courts.

Several fraternities and sororities that filed the suits in December say Harvard unfairly punishes students who join all-male or all-female organizations.

It stems from a 2016 rule saying students in single-gender clubs can't lead campus organizations or become captains of sports teams.

The national and local groups suing Harvard say the rule has forced several campus groups to close or become co-ed, including many of the school's all-women groups.

Harvard doesn't officially recognize fraternities or sororities, but several have been open to its students in the past.