Police in Iran have fired teargas and shots in the air to disperse demonstrators marking the tenth anniversary of an attack on Tehran University.Around 250 pro-reform protestors gathered at the site are said to have chanted the name of defeated presidential candiate, Mirhossein Musavi. Up to 3,000 others are reported to have taken to the surrounding streets in protest. Witnesses say police have made several arrests. Plans for the rally have been are understood to have been circulating for days on social network and opposition websites. All gatherings have been banned in a crackdown on mass protests that erupted after last month’s disputed election.