Angry supporters of Mohamed Morsy have threatened to commit suicide if the ousted president is not released and returned to his post.
Supporters affiliated to the Muslim Brotherhood, as well as others Islamist groups, demonstrated Tuesday at Nahda Square near Cairo University following deadly violence outside Republican Guard House will left 51 dead and hundreds more injured.
They threatened to commit suicide at undisclosed locations if their demands were not met.
They called on armed forces to support legitimacy.
Protesters announced rallies would last for two days until the rights of victims of the violence were restored.
Demonstrators said they would not accept anything other than the rights of the martyrs.
They added that they will stage marches on Wednesday evening heading from Nahda Square to Republican Guard House in eastern Cairo to condemn the incident.
Groups of protesters, with around 30 people wearing helmets and carrying sticks and shields, performed quasi-military exercises as a show of force that Islamist popular committees would protect pro-Morsy demonstrations from any further attacks.
Protesters stood in lines and chanted slogans.
Rabaa al-Adaweya Square meanwhile remained calm, one night after security forces shut down a sit-in outside Republican Guard House by supporters of the ousted president.
Protesters slept in makeshift tents while dozens standing on the National Alliance in Support of Legitimacy stage, in front of Rabaa al-Adaweya Mosque, chanted against Defence Minister General Abdel Fattah al-Sisi through the night.
Edited translation from Al-Masry Al-Youm
