Supporters and opponents of Egyptian President Mohammed Morsi have staged rival rallies across the country but there has been violence in the north. Tension has risen ahead of a mass protest planned by the opposition for Sunday. Thousands of Morsi supporters rallied outside the main mosque in Cairo's Nasr district. At least one person was killed in Alexandria as protestors stormed a local Muslim Brotherhood office. Dozens more were injured when anti-Morsi protestors and Islamists clashed in the northern city, the second biggest in Egypt. The office of the Muslim Brotherhood, which backs Mr. Morsi, was set ablaze and birdshot...