Maine’s education office is being ordered to ban transgender athletes from girls’ and women’s sports or face federal prosecution, an escalation in President Donald Trump’s threats to pull federal money from states and schools over transgender athletes.

The Department of Health and Human Services has given Maine 10 days to resolve Title IX violations for allowing biological males who identify as female to compete in women’s school sports. HHS’s Office for Civil Rights found the Maine Department of Education in violation of Title IX on Feb.

A notice sent recently to Maine officials by the U.S. Department of Health and Human Services accused the state of breaking federal law by “allowing male athletes to compete against female athletes in current and future athletic events.