The U.S. Department of Education announced Wednesday that California and the California Interscholastic Federation violated the civil rights of female students on the basis of sex by allowing transgender athletes to compete in school sports according to their gender identity.

Having concluded its investigation, the Trump administration is calling on California to “voluntarily agree” to change what it determined are “unlawful practices” within 10 days or risk “imminent enforcement action.”

“Although Governor Gavin Newsom admitted months ago it was ‘deeply unfair’ to allow men to compete in women’s sports, both the California Department of Education and the California Interscholastic Federation continued as recently as a few weeks ago to allow men to steal female athletes’ well-deserved accolades and to subject them to the indignity of unfair and unsafe competitions,” U.S. Secretary of Education Linda McMahon said in a statement.