University students are protesting a government crackdown on reformist student groups. This takes the form of hunger strikes, demonstrations and other non-violent actions.
The government is feuding with Saudi Arabia over Iranian accusations that Saudi Arabia is unfairly persecuting non-Moslems. One of the differences between Sunni (Saudi) and Shia (Iranian) Islam is that the Shias are more tolerant of non-Moslems. Not a lot more tolerant, but enough so that Iranian media has felt confident enough to criticize Saudi Arabia over the issue.