Some banners hanging in Tahrir Square in Cairo read, "No elections under military rule," "No constitution under military rule" and "No former regime icons for president," Ahram Online reported.
Protesters had begun arriving in Tahrir Square Friday morning for what had been billed a "save the revolution" demonstration organized by Islamist groups, including the Muslim Brotherhood, the Salafist Calling and Al-Jamaa Al-Islamiya.
Voice of America reported protesters chanted slogans against Egypt's ruling Supreme Council of the Armed Forces, and rival crowds of pro-democracy activists and Islamic fundamentalists were protesting on different corners of the square.
The election commission Thursday announced the final list of 13 candidates for president, including the top two Islamists. Ten candidates were disqualified but Ahmed Shafiq, who served under ousted leader President Hosni Mubarak during last year's uprising, was reinstated.
The first round of voting in the election is scheduled for May 23-24. If no candidate captures more than 50 percent of the vote, a runoff will be held and a winner is to be declared June 21.