"Almost every day, state security is arresting and interrogating people about the call to protest on November 11," former presidential candidate Khaled Ali wrote on Facebook after hashtags began appearing calling for the mass demonstrations.
They moreover coincide with the United Nations climate summit, which has drawn further scrutiny of Egypt's rights record, as well as calls to guarantee the right to freedom of assembly.
The measures, which have included random phone searches and summons for interrogation, began in October, according to prominent opposition lawyer.
Downtown Cairo has seen "passers-by arrested and their phones searched" for days, human rights lawyer Mahienour El-Massry tweeted.
"Why? Based on what law? And all this as they speak of a dialogue and a new republic where all opinions are welcome," Massry continued.
While its origins are unknown, the demonstration calls have been backed by several opposition figures and media based abroad.
The proposed date of the demonstration is the same as the expected arrival of US President Joe Biden for COP27, which Egypt is hosting in the remote resort town of Sharm el-Sheikh.
Ahead of the main planned protest, there have been calls on Twitter for a "dress rehearsal".
Egyptians were urged to take to the streets last Friday after a football match between the country's two biggest clubs, Al Ahly and Zamalek.
But as Friday came, cafes and restaurants around Tahrir and elsewhere had already closed their doors in response to police orders, some owners told AFP.
By the end of the match, plainclothes and uniformed officers were deployed around Tahrir, which was empty of any demonstrators.
On Friday, Amnesty International reported that Turkey-based Egyptian journalist Hossam Elghamry had been arrested by Turkish security forces, "raising fears of deportation".
Elghamry, who has since been released, had earlier tweeted that Friday would be "a dress rehearsal for Egypt #after_the_match".
Local media in Egypt reported the news, calling Elghamry a member of the Muslim Brotherhood, which was outlawed and designated a terrorist organization following the 2013 military ouster of late Islamist president Mohamed Morsi.
