A coalition of political groups called for a "Second Friday of Anger" aimed at the Supreme Council of the Armed Forces, Egypt's interim government, al-Masry al-Youm reported. Leaders said marches will begin at Cairo's major mosques after Friday prayers and head to Tahrir Square.
While most of the tens of thousands of people who were in the square Wednesday had gone, the number of tents increased Thursday. Al-Masry al-Youm estimated the crowd at 3,000.
Activists were debating the best tactics, thedailynewsegypt.com reported.
Mahmoud Salem, who blogs under the name Sandmonkey, said sit-ins and occupations at squares around Cairo would be more effective than a single large gathering in Tahrir Square.
"The military's intelligence and informants know how to disperse sit-ins in Tahrir very well, so I wouldn't recommend that," he said.
Tahrir Square was the center of demonstrations last winter that helped bring down President Hosni Mubarak.