Backers and opponents of Egypt's deposed Islamist president Mohammed Morsi began Friday to rally for rival mass demonstrations called separately by Islamists and the military, dpa reported.
Scores of anti-Islamist activists were turning out at central Cairo's Tahrir Square in response to a call made by army chief Abdel-Fattah al-Sissi, who engineered Morsi's ouster earlier this month.
Army tanks and armoured vehicles have been deployed around the iconic square as volunteers manned checkpoints to verify participants' identities. Pro-al-Sissi banners were hung across the place.
Al-Sissi has called on Egyptians to take to the streets nationwide to back a possible crackdown by the army upon Morsi's Brotherhood, which opponents accuse of inciting violence in the country since the army deposed the Islamist leader on July 3.
The Brotherhood and allied Islamists have denounced al-Sissi's call as a "declaration of civil war" and vowed to continue protests until Morsi is restored to office.
The army Thursday gave Islamists a 48-hour deadline to back down or face a clampdown.
The Brotherhood insists that its protests are peaceful and accuses the military and police of hiring thugs to attack its supporters.
The Islamist group's followers were Friday flocking to the area of Rabaa al-Adawiya in north-eastern Cairo, joining many others who have been camping there for weeks to protest what they call a military coup against Morsi, Egypt's first democratically elected president.
The demonstrations deepen the country's political polarization and raise fears about further street violence between Morsi's supporters and opponents.
Dozens have been killed in Egypt, the Arab world's most populous country, since the army removed Morsi after millions protested to demand he step down.