A spokesman for the city's judiciary, who asked not be named, explained the drive would tackle problems of "public chastity". Sixty five mannequins have been impounded so far.
He explained the crack-down on tailors' dummies was part of a larger offensive against anti-social behaviour such as vandalism and biker gangs.
Bojnourd owes its traditional religious climate to the nearby shrine city of Mashhad, a focal point of pilgrimage for the world's Shia Muslims.