Members of the Canadian media and the public have joined an international day of action to demand the release of an Egyptian-Canadian journalist and his colleagues imprisoned in Cairo.

Canadian Mohamed Fahmy and his colleagues — Australian Peter Greste and Egyptian Baher Mohamed — were detained on Dec. 29., and are being tried on charges of belonging to and aiding a terrorist organization.

Their arrests were characterized as part of a crackdown on the Muslim Brotherhood, an Islamist group that Egypt's military-backed government has branded a terrorist organization.

Rallies are being held Thursday in Toronto and Montreal to protest the detention of the Al-Jazeera English staffers.

Journalists and free speech advocates with masking tape stuck across their mouths gathered in centres in other countries as well, including London's Trafalgar Square, Lebanon's Martyrs' Square and in Kenya's capital, Nairobi.

On the Internet, journalists posted photographs of packed newsrooms bearing signs saying, "Journalism is not a crime."

Local authorities have said Al-Jazeera is biased towards the Muslim Brotherhood — an allegation the broadcaster has denied while saying its journalists were just doing their jobs.

Mideast Lebanon Al Jazeera Jailed Journalists

A Lebanese reporter who works for Al-Jazeera takes part in a sit-in, calling for the release of journalists detained by Egyptian authorities, at Martyrs' Square in Beirut, Lebanon. (Hussein Malla/Associated Press)

"We want Egypt to know that these people that are in prison are being watched by the world and that the world expects that they will be let go as soon as possible," said Daniel Lak, Al-Jazeera's correspondent in Toronto.

A trial for Fahmy and his colleagues began last week, with all three pleading not guilty to the charges against them.

The trio are being tried as part of a group of 20 individuals who authorities say worked for Al-Jazeera. At least 12 of those are being tried in abstentia.

Fahmy's family has called the charges against the 40-year-old "ridiculous" and hopes an Egyptian court will eventually dismiss the case.

The Department of Foreign Affairs has said senior Canadian officials have raised Fahmy's case with Egyptian authorities and have requested a fair and expeditious trial.

Fahmy's family moved to Canada in 1991. He lived in Montreal and Vancouver for years before eventually moving abroad for work, which included covering stories for the New York Times and CNN.