HARTFORD, Conn. (AP) — The families of three female high school runners filed a federal lawsuit Wednesday seeking to block transgender athletes in Connecticut from participating in girls sports.

Selina Soule, of Glastonbury High School, Alanna Smith, of Danbury High School, and Chelsea Mitchell, of Canton High School, are represented by the conservative nonprofit organization Alliance Defending Freedom. The organization argues that allowing athletes with male anatomy to compete has deprived their clients of track titles and scholarship opportunities.

“Forcing them to compete against boys isn’t fair, shatters their dreams, and destroys their athletic opportunities,” attorney Christiana Holcomb said in a news release. “Having separate boys’ and girls’ sports has always been based on biological differences, not what people believe about their gender, because those differences matter for fair competition.

“And forcing girls to be spectators in their own sports is completely at odds with Title IX, a federal law designed to create equal opportunities for women in education and athletics,” Holcomb said. “Connecticut’s policy violates that law and reverses nearly 50 years of advances for women.”

The lawsuit was filed against the Connecticut Association of Schools-Connecticut Interscholastic Athletic Conference and the boards of education in Bloomfied, Cromwell, Glastonbury, Canton and Danbury.

The Connecticut Association of Schools-Connecticut Interscholastic Athletic Conference has said its policy follows a state anti-discrimination law that says students must be treated in school by the gender with which they identify.

The lawsuit follows a Title IX complaint filed last June by the girls’ families and the Alliance Defending Freedom with the U.S. Education Department’s Office for Civil Rights, which is investigating the policy.

The lawsuit centers on two transgender sprinters, Terry Miller and Andraya Yearwood, who have frequently outperformed their cisgender competitors.

The two seniors have combined to win 15 girls state indoor or outdoor championship races since 2017, according to the lawsuit.

The three plaintiffs have competed directly against them, almost always losing to Miller and usually behind Yearwood. Mitchell finished third in the 2019 state championship in the girls 55-meter indoor track competition behind Miller and Yearwood.

Yearwood, of Cromwell High School, and Miller, of Bloomfield High School, have both defended their participation in girls events.

Yearwood told The Associated Press in February 2019 that there are many differences among athletes that may give one a physical advantage over another, and that she does not think she has an unfair advantage.

“One high jumper could be taller and have longer legs than another, but the other could have perfect form, and then do better,” she said. “One sprinter could have parents who spend so much money on personal training for their child, which in turn, would cause that child to run faster.”

Yearwood’s mother said the athlete had no immediate comment on Wednesday’s lawsuit. Miller did not respond to immediately respond a request for comment.

The attorneys are asking the court to prevent the transgender girls from competing while the lawsuit moves forward.

Connecticut is one of 17 states that allowed transgender high school athletes to compete without restrictions in 2019, according to Transathlete.com, which tracks state policies in high school sports across the country. Eight states had restrictions that make it difficult for transgender athletes to compete while in school, such requiring athletes to compete under the gender on their birth certificate, or allowing them to participate only after going through sex reassignment procedures or hormone therapies, according to Transathlete.

Yearwood and Miller have said they are still in the process of transitioning but have declined to provide details.