Nairobi, Kenya (CNN) -- Foreign and local journalists gathered outside the Egyptian Embassy in Nairobi on Tuesday to protest the imprisonment and demand the release of Al Jazeera East Africa correspondent Peter Greste and his colleagues.
More than a hundred journalists in Kenya's capital wore T-shirts and carried banners in solidarity with the journalists, who are imprisoned in Egypt.
"No rest till we see Greste," "Being a journalist is not a crime" and "Journalism is not terrorism" were some of the messages on display.
In the online campaign #FreeAJstaff, supporters tweeted pictures of themselves with tape over their mouths to protest the gagging of the media.
"We ask the Egyptian authorities to release them and say that their charges are baseless," said Robyn Kriel, co-chairwoman of the Foreign Correspondents Association of East Africa.
In its annual census late last year, the Committee to Protect Journalists said that at least 211 journalists were behind bars. Media analysts say that number has risen since.
After several hours of camping outside the embassy, under the watchful eye of Kenyan police, some of the organizers were let in to meet Egyptian Deputy Ambassador to Kenya Ansari Ahmed. They handed him a letter and the book "Long Walk to Freedom" by South African anti-apartheid icon Nelson Mandela.
The book was meant to inspire Greste not to lose heart while in jail, and the letter was a personal message to him signed by colleagues, friends and supporters.
"It has been 37 days now; initially we thought this situation would be resolved quickly and that you would be back in Kenya. ... Instead you are in there, languishing in prison for doing your job, for trying to get both sides of the story," it said in part.
However, Ahmed declined to receive the items. He said the request was out of his control and advised the journalists to take them to the Australian Embassy, since Greste is an Australian citizen.
Three Al Jazeera journalists detained for a month are among 20 people referred to Egypt's criminal court to face trial, Egyptian state media reported last week.
Egyptian authorities say the journalists held illegal meetings with the Muslim Brotherhood, which was declared a terrorist group in December. Greste has written in a letter released by Al Jazeera that his detention was an attack on media freedoms.
Four of the 20 defendants are foreigners: Australian Al Jazeera correspondent Peter Greste, two unidentified Englishmen and one unnamed Dutchman, state media reported.
Mohammed Adow, an Al Jazeera senior correspondent who was also part of the protest, described Greste as a man who values objectivity and always goes the extra mile.
"His detention is unfortunate and illegal, Adow said.
"We demand for his unconditional and immediate release," he added.
Members of the Foreign Correspondents Association of East Africa have vowed to continue the protests until the journalists detained in Egypt are released.