Thousands of supporters of ousted president Mohamed Morsi gathered in downtown Cairo to demand his reinstatement, leading to traffic congestion as demonstrators settled down on the street for Iftar – when Muslims break their day-long fast during the holy month of Ramadan.
Morsi was deposed by the military last week after millions of Egyptians took to the streets to demand early elections.
Hundreds of thousands of pro-Morsi protesters gathered earlier on Friday in Nasr City east of Cairo for a demonstration to press for Morsi's reinstatement.
The area has played home to a sizeable pro-Morsi sit-in since 28 June.
Demonstrators near Cairo's downtown Ramses district said they would move from their place of congregation at the Fath Mosque, moving off in several marches through various areas of the capital, state news agency MENA reported.
MENA added that protesters condemned what they view as a "coup" against Morsi and the Muslim Brotherhood – many leaders of which remain in police custody – and are calling for Morsi's return to his post and the reinstatement of the upper house of Egypt's dissolved parliament.
After removing Morsi, the army suspended the constitution, dissolved the Brotherhood-led Shura Council (upper house of parliament) and laid down a transitional roadmap jointly with opposition groups that included the appointment of the head of Egypt's constitutional court, Adly Mansour, as interim president.
Mansour has since issued a constitutional declaration setting a framework for constitutional amendments, along with early presidential and parliamentary polls.
The president's office also plans to launch an initiative aimed at fostering "national reconciliation" sometime this week.
Pro-Morsi sit-in continues
Significant numbers of Morsi supporters have been camped out at Rabaa Al-Adawiya Mosque in Nasr City since 28 June.
Protesters at Rabaa had initially congregated late last month to oppose calls for Morsi to step down, but following his 3 July ouster by the military, changed their demand to his reinstatement.
On Friday, protesters waved flags amid patriotic and pro-Morsi anthems. On the stage, a large banner reading 'Anti-coup' in English could be seen.
An imam delivered a Friday sermon to the crowds in which he mourned fallen "Islamist martyrs" and urged those assembled to continue their sit-in.
Monday saw deadly violence outside the nearby Republican Guard headquarters, when clashes between military personnel and pro-Morsi demonstrators led to the death of at least 51 of the latter and one officer.
Islamist preacher Safwat Hegazy gave a speech on the main stage at Rabaa Al-Adawiya in which he vowed that protesters would maintain their demonstrations until the president was is back in office, or would "die as martyrs."
He went on to say that the army would bow to pressure "whether they want to or not."
In Giza, marches from the Omraniya and Dokki districts reached Nahdet Misr Square, another venue where Islamists have been encamped to defend the former president's "democratic legitimacy."
The former president's supporters from Cairo and other provincial towns began gathering there on Thursday night, Al-Ahram's Arabic website reported.
Groups who oppose former president Morsi also called for mass gatherings on Friday.
The National Salvation Front, the Rebel campaign and the 30 June Front have all called for public gatherings at Tahrir Square and the Ittihadiya presidential palace.
At least 90 people have been killed and almost 2,000 injured in political unrest over the past week, heightening polarisation during the country's troubled transition to democracy.
US, Germany urge Morsi's release
The US State Department on Friday called on the Egyptian army and presidency to release Morsi, who remains in police custody, following similar calls from Germany.
However, speaking at Rabaa Al-Adawiya late Friday night, Brotherhood leading member Mohamed El-Beltagi said "our demand is not simply the release of Morsi', but his reinstatement as the legitimate leader of the country and the dismissal of Defence Minister Abdel-Fattah El-Sisi."
Morsi is being held at an unknown location since his ouster. The US had earlier condemned "arbitrary" arrests of some of the top leaders of the Muslim Brotherhood, but had refrained from referring to detainees by name.
Brotherhood second-in-command Khairat El-Shatter, is among the group's top figures arrested since Morsi's ouster.