NEW YORK (NewsNation) — A Long Island county official Thursday announced and signed a restrictive policy for transgender athletes, citing “bullying” against biological females.

The move, announced by Nassau County Executive Bruce Blakeman, says the order protects girls from unfair competition with biological boys. The order says an individual’s gender is identified as their biological sex at birth, not whether they identify as transgender.

The move not only bans transgender athletes from girls’ sports, but would also ban them from girls’ locker rooms, a change that took effect immediately.

Nassau County is not only banning the practice in Blakeman’s county, but he is also barring all girls’ sports teams and leagues from participating in competitive sports unless they agree to ban transgender competitors at Nassau County’s 100 ball fields and athletic facilities.

“It is an unfair advantage for someone who is a biological male to compete against a biological female,” said Blakeman. “And again, I view this as a form of bullying, and it will not be tolerated. We tolerate no bullying in Nassau County.”

Twenty-four states currently have some form of ban against transgender athletes.