While two jailed Al-Jazeera reporters were freed on Friday pending a retrial, rights groups said at least nine more journalists still languish in Egyptian prisons.
Mohammed Fahmy and Baher Mohammed were released nearly two weeks after their Australian colleague Peter Greste was deported under a presidential decree.
The three were arrested in late 2013 and sentenced to between seven and 10 years in jail for aiding the blacklisted Muslim Brotherhood. An appeals court in January ordered their retrial.
New York-based media watchdog the Committee to Protect Journalists (CPJ), which in 2013 rated Egypt as the third most dangerous country for journalists after Syria and Iraq, said there were nine more media workers jailed in the country.
Separately, officials at Egypt's press syndicate say at least 15 journalists are imprisoned.
Some are facing trial on several charges including rioting and belonging to a "terrorist organization."
Detainees also include citizen journalists arrested in police sweeps to quell protests backing ousted Islamist President Mohammed Mursi.
Mahmoud Abu Zeid, widely known as Shawkan, is one of the most prominent journalists held in Egypt's prisons.
Abu Zeid, a freelance photographer who has worked for photo agencies such as Demotix and Corbis, is one of the longest-detained journalists in Egypt.
He was arrested on August 14, 2013 when hundreds were killed as security forces cleared two pro-Mursi protest camps in Cairo.
He has not been convicted of any crime. For some time Abu Zeid shared a prison cell with Al-Jazeera reporter Abdullah al-Shamy, who was also arrested on the same day but released in June.
Ahmed Gamal Zeyada is another Egyptian journalist in prison. Zeyada, 23, was arrested on December 28, 2013 while covering clashes between Islamist students and security forces at al-Azhar University in Cairo.
Zeyada, an online journalist who worked for Yaqeen News Network, is on trial with 76 students on several charges, including torching the institution's faculty of commerce building.
Six of the remaining seven jailed journalists worked for Islamist media that opposed Mursi's ouster.
Mahmoud Abdel Nabi, Sami Mustafa and Abdullah al-Fakharany reported for an online citizen journalism platform called Rassd. Mohammed al-Adly worked for Amgad television, and Abdel-Rahman Shahine worked for Freedom and Justice News Gate, affiliated to Mursi's political party. Ayman Saqr worked for Al-Mesryoon newspaper.
Meanwhile, Ahmed Fouad worked for an online news website covering the Mediterranean city of Alexandria.
The annual press freedom ranking from Reporters Without Borders (RSF), which was released on Thursday, placed Egypt as the 158th worst nation out of 180.
