Thousands of protesters converged on Cairo's Tahrir Square on Friday to join a planned rally in solidarity with the recently-launched "Rebel" campaign, which aims at "withdrawing confidence" from Egyptian President Mohamed Morsi and bringing about early presidential elections.
Hundreds of marchers coming from Sayyeda Zeinab Mosque and Mostafa Mahmoud Mosque arrived in the square, before hundreds more arrived from Shubra, carrying mock coffins and raising aloft crosses in a symbolic gesture of remembrance of recent victims of sectarian violence.
Before the march at the Mostafa Mahmoud Mosque set off, some worshippers had expressed their dissatisfaction when the mosque's imam included a prayer in support of Morsi in his sermon.
As numbers swelled in Tahrir, the epicentre of the 2011 revolution, fights broke out between groups of protesters in a street off the square.
A fist-fight erupted in Mohamed Mahmoud Street after some protesters shouted "the army and people are one hand," provoking others who oppose any military intervention in the country's political affairs, reported Ahram Online's Mai Shaheen.
Another fight broke out in front of the Egyptian Museum on the other side of the square, albeit on a smaller scale, for the same reason, Shaheen added.
The Supreme Council of the Armed Forces (SCAF) was in charge for a year and a half after the fall of former president Hosni Mubarak. During its tenure, SCAF was frequently criticised for policies opponents described as repressive, such as holding military trials for civilian defendants.
Several protesters also threw stones towards the interior ministry's headquarters from behind one of the walls blocking the roads leading to the building. The police did not respond however, and the protesters soon returned to Tahrir.
Many clashes have taken place between police forces and civilians since the 2011 revolution.
Officially launched on 1 May, the 'Rebel' campaign is a grassroots movement aimed at registering opposition to President Morsi and forcing him to call early presidential elections by collecting as many as 15 million signatures by 30 June. The group says it has already collected two million names.
Campaigners for the signature drive said they aim to intensify their presence in the square to collect the maximum number of signatures, Egyptian state news agency MENA reported.
Protesters put up a platform in the square, and pictures of slain protesters were displayed in the square's central garden. By sunset, the numbers in the square and the surrounding streets had reached several thousand.
Security has been tightened around the usual protest hotspots, including the interior ministry, the Cabinet headquarters, the Shura Council, the presidential palace and the headquarters of the Muslim Brotherhood, from which President Morsi hails.
A number of political parties have participated in the protests, including the Constitution Party, the Free Egyptians Party, the Socialist Popular Alliance, the Karama party, the Free Front for Peaceful Change, the Popular Current, the Kefaya movement, and the April 6 Youth Movement.
Major demands of the anti-government demonstration include snap presidential elections, the release of detained political activists, and a new constitution.
A short distance away, a few dozen had gathered outside the High Court, a site of a number of recent protests, to call for the fulfillment of the "revolution's demands," according to state news agency MENA.
In the coastal city of Alexandria, hundreds of protesters marched to Qaid Ibrahim Square in the afternoonm in support of the petition against Morsi, condemning the "Brotherhoodisation of the state," Al-Ahram's Arabic-language news website reported.
In the Nile Delta city of Mansoura, meanwhile, dozens of activists rallied in front of the local offices of the state security body on Friday evening, chanting against the Muslim Brotherhood and the Freedom and Justice Party.
They were incensed after seven of the city's activists were charged with attacking the offices.
Moving to the northern Damietta city, a coordinator of the ‘Rebel’ campaign said he expects to have 100,000 signatures within the next few days.
"We are supported by the April 6 Youth Movement, the Popular Current, the Free Egyptians Party and ordinary people who are against the Brotherhood’s rule," Mohamed Gomaa was quoted as saying by Ahram's Arabic-language news website.
Egypt's opposition has grown increasingly discontent with President Morsi's Islamist-led regime's perceived attempts to monopolise state institutions and smother dissent.
Opposition figures also criticised Egypt's new constitution, which was drafted by an Islamist-dominated assembly and passed by popular referendum last year.
Several political activists as well as media figures and journalists have been recently arrested or questioned over a range of charges, including inciting violence as well as insulting and defaming the president.