At least 1,900 people have been detained since protests against President Abdel Fattah al-Sisi began in Cairo and other Egyptian cities last Friday, the head of a rights monitoring group said.
Gamal Eid, head of the Arab Network for Human Rights Information, said the arrests had been made between Friday and Wednesday and described them as part of the “most violent campaign in Egypt’s (modern) history”.
An interior ministry spokesman could not immediately be reached for comment.
Protesters chanting “Leave, Sisi” gathered in Cairo and other cities on Friday following online calls for demonstrations against alleged government corruption. The protests continued in the Red Sea city of Suez on Saturday.
There have been calls for similar protests this Friday, though supporters of the government are also planning mass rallies to show their support for Sisi.
Security forces have stepped up their presence in main squares in major cities and have been checking mobile phones for political content.
Sisi, who came to power after leading the overthrow of Islamist former president Mohamed Mursi, has overseen a broad crackdown on dissent that has extended to liberal as well as Islamist groups, and which rights groups say is the most severe in living memory.
