A federal judge on Friday blocked a southern Kentucky high school from including prayers in its graduation ceremony Friday evening.

The American Civil Liberties Union filed a federal lawsuit this week seeking a restraining order on behalf of an unidentified student at Russell County High School in Russell Springs, 90 miles south of Louisville.

The student had appealed to principal Darren Gossage to drop the prayer from the Friday evening ceremony, but the principal refused, ACLU attorney Lili Lutgens said.

Lutgens argued that any prayer would be unconstitutional because it would endorse a specific religion and religious views. U.S. District Judge Joseph McKinley granted the temporary restraining order Friday morning, prohibiting the school district from having even a student representative say a prayer during the ceremony.

A call to Gossage's office was not immediately returned.

The U.S. Supreme Court has held that clergy-led prayer in public school graduations and sporting events is prohibited. Lutgens said earlier this week that student-initiated prayer before or after the ceremony would be OK.