Thousands of Egyptians supporting ousted President Mohamed Morsi are massed in Cairo demanding he be reinstated.
Many in the crowd waved Egyptian flags and held up signs of the deposed president late Thursday while celebrating Eid al-Fitr, the feast that marks the end of the holy month of Ramadan. The government had issued warnings for supporters of Morsi to vacate the sites.
Opponents of Morsi gathered Thursday in Cairo's Tahrir Square.
Egypt is facing a political crisis that the country's military-backed government and Islamist opposition have been unable to defuse.
On Wednesday, interim President Adly Mansour said this week's efforts by international envoys to bridge the political divide had failed. He blamed Morsi's Muslim Brotherhood for the failure.
The United States and European Union say the political divide has created a fragile situation that could spark more bloodshed and impede Egypt's economic recovery.
Egypt's interim authorities have detained top members of the Muslim Brotherhood, including Morsi, since ousting him from power on July 3. The army has installed an interim government, while the Muslim Brotherhood insists the Islamist leader be reinstated.
Morsi took office one year earlier as Egypt's first democratically-elected president, but critics accused him of consolidating power in the hands of the Brotherhood and threatening a secular lifestyle.