Ahead of World Press Freedom Day, Egypt's journalists' union has demanded the dismissal of the interior minister after two journalists were arrested at its headquarters in Cairo overnight.
The union also called for a sit-in to protest against the security forces' "blatant barbarism and aggression on the dignity of the press", it said in a press release.
The interior ministry has denied the union was raided, but confirmed the arrests of the journalists, who are accused of inciting protests.
The two men work for the website Bawabet Yanayer (January Gate), which is critical of President Abdul Fattah al-Sisi's government.
The journalists' union said the raid was by security forces “whose blatant barbarism and aggression on the dignity of the press and journalists and their syndicate has surprised the journalistic community and the Egyptian people".
It called for an "open-ended" sit-in outside the union's headquarters running at least until a general assembly meeting on Wednesday.
Dozens of people gathered on the steps of the building, chanting "journalists are not terrorists", the Associated Press reported.
Members of the union said dozens of police officers had been involved in Sunday night's operation to arrest the two reporters and the BBC reports the opposition Egyptian Social Democratic Party denounced what it called "the storming of the press syndicate".
The interior ministry insisted that it had not been a raid and no force was used.
State prosecutors have been quoted as saying the two journalists and seven others working for Bawabet Yanayer were being investigated on suspicion of "using fake news" to incite protesters to "clash with police forces and storm public and vital establishments" last Monday, when the union's headquarters were sealed off by police that day after being named as a rallying point for protests against President Sisi's decision to hand back control to Saudi Arabia of two islands in the Red Sea - a move critics have condemned as unconstitutional and lacking in transparency, the BBC reports.
Sisi has suppressed all dissent since leading the military's overthrow of democratically elected President Mohammed Morsi
According to NGO Reporters Without Borders, Egypt is ranked 159th out of 180 countries in the 2016 World Press Freedom Index.
Meanwhile, the Guardian reports the police prevented hundreds of workers from holding a meeting at the building to commemorate International Workers’ Day, prompting independent trade union leaders to urge the government to allow them freedom of assembly.