COEUR D'ALENE, Idaho (AP) — A Christian advocacy group has filed a federal lawsuit against an Idaho city, contending its anti-discrimination ordinance compels a wedding chapel's Christian owners, who are also ministers, to perform same-sex marriages.

The Alliance Defending Freedom contends that the Coeur d'Alene ordinance compels Hitching Post owners Don and Lynn Knapp to perform same-sex marriages in violation of their religious beliefs and constitutional rights.

In a response letter, Coeur d'Alene City Attorney Mike Gridley said that because the wedding chapel is registered as a for-profit business, it likely would be violating city code if it turns away same-sex couples.

On Oct. 6, the Knapps filed with the state as a religious organization. Gridley, in his letter, says if the Knapps are truly operating a not-for-profit religious corporation, they'll be exempt from the city ordinance.