Syrian opposition groups are calling for mass protests a day after a raid by the regime security forces on dormitories at Aleppo University killed four students and forced the closure of the state-run school, AP reported. Friday is the day of weekly anti-government protests in Syria, when thousands of demonstrators regularly take to the street calling for President Bashar Assad's ouster. The university incident sparked outrage in the northwestern city of Aleppo and activists said new protests were expected. The Syrian National Council opposition group urged students across Syria to stage a strike. The group also said the international community through its silence was encouraging the Assad regime to continue with its brutal crackdown on dissent.