Clashes erupted on Friday amid heavy troop deployment in Egypt with Muslim Brotherhood protesters thronging the streets as part of their call for a "Friday of anger" to protest a brutal crackdown on supporters of ousted president Mohammed Morsi that killed over 638 people.
Military vehicles were deployed across Cairo and Giza, taking up positions in squares and securing important institutions, the state-run media reported.
Thousands of pro-Morsi supporters took to the streets after Friday prayers for marches as part of what they dubbed as a "Friday of anger" in defiance of the military-imposed state of emergency.
Egyptian security officials say death toll in clashes across country rises to at least 60.
Armoured vehicles and barbed wires blocked all entrances to Tahrir Square, and 22 armoured vehicles were in Mustafa Mahmoud Square.
Security forces fired birdshot and tear gas to stop supporters from reaching a government building in the northern Egyptian city of Tanta.
The Muslim Brotherhood had promised huge protests on Friday, and Egypt's military government showed no sign of easing its crackdown, setting the stage for what could become another catastrophic encounter of security forces and protesters.
"The struggle to overthrow this illegitimate regime is an obligation," the Muslim Brotherhood said on its website on Friday, while urging people to protest peacefully.
The state-run media said the military increased checkpoints at all entrances to Cairo to prevent arms smuggling to protesters. Also today, at least 20 police officers were wounded when assailants opened fire on two security cars north of Cairo.
The announcement to hold protests came after hundreds of people were killed when security forces cleared two pro-Morsi protest camps at Rabaa al-Adaweya and al-Nahda, ending sit-ins that began after the army toppled Morsi on July 3.
"Anti-coup rallies tomorrow will depart from all mosques of Cairo and head towards Ramsis square after Jumaa prayer in 'Friday of Anger'," Muslim Brotherhood spokesman Gehad el-Haddad wrote on his Twitter account on Thursday.
The health ministry spokesman on Thursday said death toll from nationwide violence in Egypt has climbed to 638, making it the bloodiest day since the Arab Spring in 2011 toppled longtime President Hosni Mubarak in a popular uprising.