By DAVID D. KIRKPATRICK
Egyptâ€™s military rulers and the Muslim Brotherhood escalated their confrontation on Friday as the generals threatened to use â€œthe utmost firmnessâ€ to preserve their authority and the Islamists presented a reunited front with some of their former allies from the revolt against Hosni Mubarak.
Supporters of Mohamed Morsi, the Muslim Brotherhoodâ€™s presidential candidate, protest against the military’s tightening grasp on political power in Tahrir Square.
More than 100,000 protesters poured into Tahrir Square for a fourth day, demanding that the generals cede power to elected civilians at the end of the month as they had promised. But anxiety was high, and there was talk of a potential explosion after a state-run Web site floated rumors that the election commission would invalidate the results of last weekendâ€™s presidential runoff and declare Ahmed Shafik, a former air force general, the next president. A public vote count showed that the Muslim Brotherhoodâ€™s candidate, Mohamed Morsi, had won. MORE from NYTIMES