Army and police forces intensified security in Cairo's Tahrir, Rabaa, and Nahda squares on Friday morning in anticipation of protests which the National Coalition for Supporting Legitimacy has called for.
The alliance, which backs ousted President Mohamed Mursi, has called for demonstrations under the title "Our Constitution is 2012th" to urge people to boycott the referendum on the newly-drafted constitution.
Taking part in the referendum, which is expected to be held on 14 and 15 January, is a betrayal of the martyrs, the coalition stated.
The 2012 constitution which was suspended after Mursi's removal from power is "the country's legitimate constitution", it added.
The state-run news agency MENA correspondent reported heavy deployment of army vehicles on all entrances to Tahrir Square.
Central security forces were deployed in Simon Bolivar and Ramsis squares in addition to the Egyptian Museum's parameters.
Security forces and armoured vehicles were stationed near Rabaa al-Adaweya Mosque while four military vehicles and barbed wire were deployed in Tayaran Street to be used in case blocking traffic is required.