Iran: What is the Basij?

Rand (Pdf):

In the provinces, the Basij present a more benign face through construction projects and disaster relief, while in urban areas, they are more apt to be seen quite negatively, quashing civil society activities, arresting dissidents, and confronting reformist student groups on campuses. Urban sentiments may be, moreover, affected by the Basij’s affilia-tion with the “pressure groups” or hardline vigilantes, of which Ansar-e Hezbollah is the most widely known.