CAIRO (AP) -- Thousands of protesters returned to downtown Cairo's Tahrir Square Friday for what they called a "second revolution," calling for Egypt's military rulers to speed up the pace of democratic reforms in a country that is still charting its political future.
Protesters carried banners reading the "Egyptian revolution is not over" and chanted the slogan.
Christians and Muslims took turns praying in Tahrir Square, as they did in the protests that forced the ouster of former President Hosni Mubarak in February. Sectarian clashes have turned deadly since the revolution.
The ruling military warned that "dubious" elements may try to cause chaos during Friday's protests, and said it would stay clear of the protest area to avoid any friction.
Mohamed ElBaradei, the Egyptian Nobel Peace Prize winner and a reform leader, said that he was "seriously concerned about the absence of security forces."
The military's leadership of the country's democratic transition has left many protesters dissatisfied.
"I came here because I didn't feel that Egypt changed," technician Raafat Hendi said, under huge posters calling for a new constitution.
Some critics accuse the military rulers of collaborating with the former regime and being too lenient in its prosecution of Mubarak, his family and regime members. Mubarak now faces trial on charges of conspiring to kill protesters.
"Our biggest fault is that we left Tahrir Square before seeing Mubarak inside a courtroom being tried," 24-year-old salesman Ahmed Shawqi said.
Two days before the protest, the prosecutor general ordered Mubarak and his sons to be tried over charges of ordering the killing of protesters during the uprising, along with other charges.
The step was seen as a way to prevent protesters from returning to Tahrir Square.
The Muslim Brotherhood, Egypt's best organized political force, opposed the protest and called it an attempt to drive a wedge between the military and the people. The Brotherhood's absence will test the ability of liberal and secular groups to launch their own sustained opposition movement.
Some liberal groups are calling for planned parliamentary elections, now set for September, to be pushed back so that they will have more time to prepare. The Brotherhood, however, stands to make major gains and wants the vote to go ahead.
The protest movement wants to oust the ruling Armed Forces Council and replace it with a civilian council. Protesters accuse the army of using excessive force in cracking down on peaceful protesters since Mubarak's ouster, sending thousands to military tribunals and detaining young protesters.1
A joint statement by four liberal and secular groups called for postponing the September elections, drafting basic principles that guarantee that Egypt is a civil state and ending military tribunals.
The statement reflects worries of many political groups that the Brotherhood is poised to win a big portion of parliament.
Some protesters are demanding a new constitution prior to elections, a divisive issue.
"We can't go to elections without having a constitution first," accountant Ezz Eldin Hamid, 29, said. "You put the plan first then go to the game, not the other way around."
A referendum that passed in March with the backing of the military and the Brotherhood paved the way for parliamentary and presidential elections. It mandated that the country's new constitution will be written by a committee selected by the new parliament.
The protest movement fears a growing convergence of opinions between the Islamists and the military.
The Brotherhood, banned in 1954, became a political force after renouncing violence in the 1970s. Eventually it became the most formidable opponent to Mubarak's regime, though it was still banned as a political party.
When Mubarak fell, the Brotherhood stood ready with a huge network of social services and supporters.