we don't know if these are regular police as opposed to "religious" police. I suspect that there is some sort of women's auxilary to the regular police to deal with the fact that men aren't allowed to touch women so someone has to deal with female criminals.
Iran does not have a special "religious" police like Saudi. There was a special "Komite" force that was merged into regular police in late 80s. The regular police now handles all issues including veils and lipsticks etc.
BTW it seems several different groups are being confused with each other here. The tough, burly guys you see in most pictures from past week are the anti-riot squad. Those guys are especially hired and trained for that purpose. Bassij is a volunteer force whose members are mostly young local men and teenagers and are associated with local neighborhood mosque. It has a loose hierarchy and is mostly local. Then there are special paramilitary groups who do not officially operate as part of revolutionary guards or bassij, but do the dirty works when called upon. They are probably in the range of a few hundreds in Tehran and motivated by religious or revolutionary zeal, connected to specific hardline figures behind the scene and operate based on their orders. This last group is alleged to have been responsible for attacks on university dorms in 1999 and last week.