Security has been stepped up in the Egyptian capital, Cairo, on the fifth anniversary of the start of the uprising that toppled Hosni Mubarak.
Police are deployed near Tahrir Square, the symbolic centre of the uprising.
Thousands of homes have been raided, as the authorities look for people who might be planning protests against President Abdul Fattah al-Sisi.
Local and international human rights activists say the situation in the country has never been worse.
Mr Sisi led the military’s overthrow of Mubarak’s Islamist successor, Mohammed Morsi, in 2013 following mass protests.
Since then, more than 1,000 people have been killed and 40,000 are believed to have been jailed in a sweeping crackdown on dissent.
Most of them have been supporters of the outlawed Muslim Brotherhood, but secular activists have also been prosecuted for breaking an anti-protest law.
There is little trace of the revolution that swept an autocrat from power five years ago, and Egypt’s latest strongman is keen to keep it that way, reports the BBC’s Orla Guerin in Cairo.
Mr Sisi, a retired field marshal who was elected president in 2014, has vowed that there will be a firm response to any unrest on the anniversary.