Ahmadiyah and its sub-sect Salihiyyah preached a puritanical form of Islam, and have rejected the popular Sufi practice of tawassul (visiting the tombs of saints to ask mediation). B. G. Martin states that these two orders shared some of the views of the Wahhabis of Arabia. The religious differences between Qaadiriya and Salihiyya were controversial, as Salihis continued to oppose the Qadiris' practice of tawassul, and claimed the act to be invalid and improper religious activity.