A wave of clashes across a number of Egypt\'s northern provinces have left seven people dead and 616 injured, the ministry of health said Saturday in a statement. Supporters and opponents of President Mohamed Morsy slipped into violence ahead of mass protests for the opposition planned for Sunday. Since the breakout of scuffles on Wednesday, three people died in Mansoura and a fourth in Zagazig, both in the Nile Delta region. In Alexandria, two people died yesterday including a 21-year-old U.S. national who was stabbed to death in the country\'s second largest city. The other fatality in Alexandria was shot dead in the head. The last of the seven cases was reported in Port Said as an explosive device went off amidst a group of protestors. Several people were also wounded. Of the 616 injured, 480 left hospitals after receiving the necessary treatment, the ministry said in the statement.