Around 100 Egyptian journalists staged a protest in central Cairo on Tuesday against the arrest of colleagues for covering demonstrations opposing President Abdel Fattah al Sisi.
Security forces arrested at least 33 reporters trying to cover small anti-government protests in Cairo on Monday that were dispersed with tear gas, according to the New York-based Committee to Protect Journalists.
On Tuesday, some 100 reporters gathered in front of the headquarters of the journalists' union, witnesses said.
Yehia Qalash, head of the union, said security forces had prevented dozens of accredited journalists entering the building on Monday. "This kind of incident has not happened for years," he said in a statement.
There was no immediate comment from authorities.
Sisi has faced a wave of public criticism for agreeing to cede control of the uninhabited Red Sea islands of Tiran and Sanafir to Saudi Arabia.
Saudi and Egyptian officials say the islands belong to Saudi Arabia and were only under Egyptian control because Riyadh had asked Egypt in 1950 to protect them.
Sisi's controversial rule may be under threat, while the former head of the armed forces has also come under pressure from a faltering economy and allegations of police abuses, some of the motives for the uprising that unseated democratically elected president Hosni Mubarak in a 2011 coup.