The head of Egypt's press syndicate and two colleagues were in custody Monday after being charged with harboring journalists and publishing false news, a lawyer and one of them said.
The arrests, which Amnesty International denounced as a "draconian clampdown" on media freedom in Egypt, comes weeks after the arrest of two reporters on allegations of incitement to protest.
Union chief Yahiya Kallash had denounced the arrests earlier this month and told a news conference that President Abdel Fattah al-Sisi's government is "escalating the war against journalism and journalists".
On Sunday, the Cairo prosecutor summoned Kallash, union secretary general Gamal Elbashy and the head of its freedoms committee Gamal Abd el-Rahim for questioning, the latter told AFP.
Twelve hours later he charged the three with having "harbored fugitives" and "publishing false news", Abd el-Rahim and Elbashy's lawyer Abd al-Rady said.
The prosecutor then ordered the release of the three on condition that they post bail of 10,000 Egyptian pounds (1,000 euros, $1,100) each, until the outcome of the investigation.
"We refused to pay," Abd el-Rahim said by mobile phone.
As a result they were kept in custody until a decision by the prosecutor, who could revoke the bail or remand them in custody for four days.
Amnesty's deputy director for the Middle East and North Africa, Magdalena Mughrabi, said the arrest "signals a dangerous escalation of the Egyptian authorities' draconian clampdown on freedom of expression and demonstrates the extreme measures the authorities are prepared to take in order to tighten their iron grip on power".
By prosecuting them, the authorities seek "to send a strong message to intimidate all journalists into silence", she said, calling for their release and for the charges to be dropped.
Rights activists accuse Sisi of running an ultra-authoritarian regime that has violently suppressed all opposition since toppling Islamist president Mohamed Morsi in 2013.
On May 1, police sparked media and opposition outrage by storming the journalists' union building in an unprecedented raid and arresting reporters Amr Badr and Mahmud al-Sakka.
Badr and Sakka work for the opposition website Babawet Yanayer and were both accused of incitement to protest in violation of the law.
The prosecutor said the pair would be held as part of an investigation which also includes allegations that they had called for a "coup".
Amnesty said the raid on the union building "was unprecedented. It is the most brazen attack on the media the country has seen in decades."SHOW MORE