Supporters of deposed president Mohamed Morsi march in Cairo and Giza, security measures taken to prevent clashes with rival protesters.
Mass protests in support of deposed president Mohamed Morsi are underway across Cairo.
Demonstrators condemn what they say was a military coup against the country's democratically elected leader.
Meanwhile, anti-Morsi protests are taking place at the Ittihadiya presidential palace and Tahrir Square.
A number of pro-Morsi marches converged outside Cairo University in Giza early Friday afternoon.
Other marches made their way to Rabaa Al-Adawiya Mosque in Cairo's Nasr City, where Morsi supporters have been protesting since his ouster.
Military helicopters have flown endless sorties over Pro-Morsi rallies across the capital.
Protest leaders at Rabaa Al-Adawiya called on demonstrators to march to the nearby Republican Guard headquarters, the venue of clashes between Morsi supporters and the army that killed at least fifty-one on 8 July.
Ahram Online reporter Ahmed Eleiba said soldiers had stopped tens of thousands of Morsi supporters en route from Rabaa Al-Adawiya Mosque to Abbassiya where the Ministry of Defence is located.
"Soldiers have been heavily deployed along Salah Salem Road in Nasr City and other major streets near the march."
Muslim Brotherhood leaders are at the march, Eleiba added. Protesters were chanting "Peaceful, peaceful!"
"Egyptians participated today after they recognized that 30 June [protests] were exploited to carry out a coup against the democratic course, and that their freedom, dignity and right to choose have been attacked," Muslim Brotherhood spokesman Uasser Mehrez said on Friday.
He also condemned what he described as widespread media blackout against Islamist protests.
Meanwhile, well-known writer Mohamed Abdel Kodous, who was taking part in a pro-Morsi Giza march, said protesters will remain steadfast until the president and the legitimacy is back, Al-Dostour Al-Assly reported.
The pro-Brotherood writer, who is a longstanding member of the executive board of the Journalists' Syndicate, said that no negotiations with the army will take place unless arrested Brotherhood leaders are released and the freezing of their assets is lifted.
Abdel Kodous went on, however, to slam the 'extremist' discourse at the main pro-Morsi vigil outside Rabaa Al-Adawiya mosque saying it has repulsed the public.
Anti-Morsi protesters have said they are concerned that supporters of the ex-president will approach Tahrir Square and the presidential palace, raising the specter of fresh violence.
Security measures have been stepped in the vicinity of Tahrir Square in an attempt to prevent clashes.
Storming hospital
Tens of Morsi loyalists have stormed Friday the Abbasiya Hospital for Mental illnesses, climbing through the fences before setting camp in the hospital's garden.
The move comes after roughly five thousand pro-Morsi protesters, according to Ahram Arabic Website, blocked the Salah Salem road in both directions near the Abbasiya Hospital, causing the traffic to come to a standstill.
Pictures of storming the hospital grounds have been circulating the social media websites by passengers in grounded vehicles.
Nationwide
Supporters of ousted president Mohamed Morsi protested across Egypt's governorates on Friday.
Thousands gathered at Alexandria's Al-Qaed Ibrahim Mosque and chanted anti-military slogans such as "[army chief] El-Sisi, Morsi is my president."
In Gharbiya's Tanta hundreds called for Morsi's return to the presidency.
In Sharqiya's Zagazig protesters chanted slogans such as "Say it strong, Morsi is the president" and "We are not afraid of the thugs, we will protect ourselves by legitimacy."
The army committed a coup against Egypt's legitimate president, Ahmed Shehata, the Freedom and Justice Party's leader in Zagazig, told Al-Ahram Arabic news website.
Hundreds gathered in Fayoum after Friday prayers. They called for army chief Abdel-Fattah El-Sisi to stand trial for "carrying out a coup" against Morsi.
In Upper Egypt's Beni Suef, thousands called for the reinstatement of Morsi and the suspended constitution. They chanted against El-Sisi and the 'pro-coup' media.
Thousands rallied in Marsa Matrouh in north western Egypt after Friday prayers.
[This article originally appeared on Ahram Online.]