Police in the central Iranian city of Isfahan detained a large number of mourners for mutilating themselves with knives during the ceremonies to mark the anniversary of the death of one of Shiite Islam's most revered figures, the official IRNA news agency reported on Sunday. Every year millions of Iranian Shiites pour into streets for Ashoura, marking the 7th century death of Prophet Muhammad's grandson Hussein and many flagellate themselves in memory of his suffering. Some Shiites take it to the extreme of self mutilation to show their deep piety but the practice is considered illegal by religious authorities. "These people were disturbing the public order," said police spokesman Col. Alinaqi Alavi, in central Iranian city of Isfahan, according to the agency. "They were using daggers as well as slashing their shoulders with spiked chains."