WASHINGTON: A US-based Sikh advocacy group has sought UN intervention to pressure India into passing a law for separate registration of Sikh marriages, as done in the case of other minorities. The Sikhs for Justice (SFJ) Wednesday submitted a memorandum to UN Special Rapporteur on Freedom of Religion or Belief Heiner Bielefeldt seeking UN intervention to impress India "to amend article 25 of the Indian Constitution to restore the independent status of Sikhism". Prime Minister Manmohan Singh's government has refused to pass an act for registration of Sikh marriages SFJ said.