BOSTON — A national women’s rights group and three Massachusetts women filed a lawsuit Thursday challenging the U.S. Education Department’s new guidance on investigating campus sexual assaults.

The Los Angeles-based Equal Means Equal and the three women, who have separately accused their colleges of mishandling complaints of sexual assault, say the new guidance is discriminatory and violates state and federal civil rights laws. They’re asking the U.S. District Court in Massachusetts to suspend the rules and prevent schools across the country from adopting them.

An Education Department spokeswoman did not immediately provide comment.

On Sept. 22, Education Secretary Betsy DeVos scrapped federal rules that were created under President Barack Obama and replaced them with interim guidance while the Education Department crafts new ones. Among other changes, her guidance allows schools to use a higher standard of evidence for reviewing complaints than the previous rules allowed.

The lawsuit says the change allows schools to apply a tougher standard of evidence for abuses based on sex than they can for other civil rights violations, such as those based on race or nationality. It alleges the disparity violates Title IX, a federal law forbidding discrimination based on sex in education.

The suit adds that DeVos’ rules violate federal law by telling schools to use narrower criminal definitions of sexual wrongdoing than those found in the Title IX law. It’s among nine allegations of violations included in the complaint.

“Ironically we have the secretary of education issuing discriminatory rules that apply only to violence against women and subject only victims of sex-based harm to second-class treatment on college campuses,” Wendy Murphy, a Boston lawyer who filed the suit, told reporters outside the city’s federal courthouse Thursday. “That is unconscionable, that is unacceptable, and it is unconstitutional.”

The three women, who aren’t named in the lawsuit, say the new rules under President Donald Trump’s administration jeopardize cases they filed against their colleges alleging Title IX violations. Two say they have ongoing cases being handled by the Education Department against Stonehill College in Easton, Massachusetts, and the Art Institute of Chicago in Illinois. The other woman is suing Boston University in civil court.

Both women with federal cases say they were unable to find out from the department whether the new rules would apply to their cases. Their lawsuit seeks expedited processing, saying it’s urgent because the rules could discourage other students from reporting sexual assaults on their campuses.

Advocates for sexual assault victims say it’s believed to be the nation’s first lawsuit over the department’s new sexual assault rules, but it follows a string of other suits against DeVos, a Republican, and the department in recent months.

Democratic attorneys general from more than a dozen states have filed two lawsuits against DeVos since July over her decision to halt Obama-era rules meant to protect students from fraudulent for-profit colleges. The National Women’s Law Center sued the department in June, saying it failed to provide records about sexual harassment.

Kamala Lopez, executive director of Equal Means Equal, said her group is planning to file other lawsuits across the country similar to the Boston complaint.

“We intend to pursue these types of cases in every jurisdiction in this country as part of our declared commitment to secure full equality for all American women and girls,” she said.