(Bloomberg) -- Harvard College’s sanctions against exclusive all-male "final" clubs and other single-sex social clubs is "punishing" the school’s Greek organizations, especially women’s, a group of sororities and fraternities alleged in two lawsuits.

The suits, filed Monday in federal and state courts in Massachusetts, claim that "Harvard has engaged in an aggressive campaign of intimidation, threats and coercion against all students who join single-sex organizations and advocate for their continued existence" -- to the point of suggesting that a student who joins such a group could be expelled. The college has singled out students who join such clubs for "scathing criticism," according to the plaintiffs.

The lawsuits demonstrate the challenge facing colleges that take on powerful fraternities and sororities, which have long fought in court to preserve their privileged positions on campus. Congress, which has many members who belonged to Greek-letter organizations, specifically excluded them from Title IX, the federal law that prohibits gender discrimination at educational institutions.

According to the plaintiffs, by banning single-sex organizations on campus Harvard has "succeeded perversely" in eliminating nearly every women’s social organization previously available to female students at the school. Almost all of its all-women social clubs have closed their doors or renounced their status as women’s social organizations and become co-ed, the suit says.

"To be sure, the sanctions policy has also seriously harmed Harvard undergraduates’ fraternities and all-male final clubs and their members," according to the plaintiffs. "But women and their former all-female social clubs have suffered the most" because, one of the suits claims, they have "lost access to places they once called their own."

Rachael Dane, a spokeswoman for Harvard, didn’t have an immediate comment on the complaints, which allege discrimination and violations of federal civil rights law on the basis of sex in an education program.

All but one of Harvard’s final clubs -- Porcellian, Harvard’s oldest --began as local branches of fraternities. The college has sought to phase out the off-campus groups, including all-male final clubs that count U.S. presidents and other power brokers among their alumni. In 2016, a university task force led by the dean said the organizations encouraged an environment where men vied with each other for “sexual conquests,” leading to reports of sexual assaults and harassment.

Harvard’s policy, endorsed by then-president Drew Faust, the first woman to lead the school, didn’t amount to a ban. Instead, starting with the Class of 2021, the rules exclude members of single-sex clubs from leading sports teams and recognized student groups and from being endorsed for fellowships such as the Rhodes and Marshall scholarships.

Even outside of the clubs, many at the university, including members of Harvard Law School, have voiced free-association concerns about the measures. The sororities in particular have asked why they should be subject to restrictions. Only a handful of private institutions, including Williams College, have banned fraternities.

The plaintiffs include fraternity Sigma Alpha Epsilon and sorority Kappa Alpha Theta.

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