Cairo (CNN) -- Tens of thousands of Egyptians turned out in Cairo's Tahrir Square on Friday to protest plans for a constitution that would shield the military from public oversight. The throng, dominated by Islamist parties but also including secular forces, comes ahead of upcoming parliamentary elections set to begin on November 28. Egypt has been ruled by the Supreme Council of the Armed Forces since the departure of President Hosni Mubarak earlier this year. The military said it wants to transfer power to a civilian parliament and president. But protesters are upset about proposed principles for the constitution, in which the military's budget would not be scrutinized by civilian powers. They worry that the military would be shaped as a state within a state. The outpouring reflects the power of Islamist forces in Egypt, particularly the Muslim Brotherhood's Freedom and Justice Party. The demonstrations occurred a day after hundreds of Coptic Christians marching in Cairo were attacked by unknown assailants. At least 32 people, including two police officers, were injured. They were heading to Cairo's Tahrir Square to commemorate the deaths of pro-Coptic protesters killed in clashes in the Egyptian capital last month. Problems between Egypt's Muslim majority and the Copts have been on the rise in recent months, with a number of violent clashes reported between the two groups.