CAIRO, Jan 10 (Aswat Masriya)- Police and army forces tightened security on Friday at Cairo's Rabaa and Mostafa Mahmoud squares in anticipation of rallies which the Islamist National Coalition for Supporting Legitimacy has called for.

The alliance, which backs former President Mohamed Mursi, has called on its supporters to rally every day during the next week to fail the upcoming constitutional referendum.

Voting on the newly-drafted constitution is expected to take place on 14 and 15 January.

Armoured vehicles and barbed wire were deployed in Nasr Street in Cairo's Nasr City, Akhbar Masr website reported.

Police and army forces also deployed a number of armoured vehicles to Mostafa Mahmoud Square in Mohandessin but did not seal the square to traffic.

Clashes flared up last Tuesday between security forces and Muslim Brotherhood supporters in Mohandessin's Gameat al-Dowal Street. The police tear-gassed the demonstrators to disperse them.

Supporters of the deposed president have been staging demonstrations regularly since July in order to protest against what they called the coup against legitimacy.

Egypt's army ousted the former Islamist president following mass protests against his ruling.