CAIRO, Egypt -- An Egyptian-Canadian journalist imprisoned in Cairo told an Egyptian court Wednesday that he could "never possibly betray his country," testifying in a case accusing him and other colleagues of being terrorists.

Mohamed Fahmy -- who is the acting Egypt bureau chief for satellite news broadcaster Al-Jazeera English -- addressed the court, saying he works as a journalist and is from a conservative and patriotic family from Port Said.

He appeared with his arm in a sling and asked for the court to release him for treatment for the injury, which he said he suffered before being arrested.

Egypt's state MENA news agency reported that the judge adjourned the trial until March 24 after hearing Fahmy speak.

Fahmy is on trial with two other Al-Jazeera English journalists and 17 other defendants on charges accusing them of joining a terrorist group, aiding a terrorist group, and endangering national security.

Authorities accuse Al-Jazeera of being a platform for ousted Islamist president Mohammed Morsi's supporters and his Muslim Brotherhood group. The network denies that, saying its journalists were only doing their jobs.

Those arrested include Fahmy, Australian award-winning correspondent Peter Greste and Egyptian producer Baher Mohamed, who have been behind bars since Dec. 29.

All have pleaded not guilty. Others are being tried in absentia.

During Wednesday's hearing, defence lawyer Khaled Abu Bakr asked that the court review reports filed by the journalists, while also asking for an independent panel of media professors to review the footage and decide whether it could be a threat to Egypt's national security.

The judge denied the request, MENA reported, saying it was up to the court to decide whether the videos were a threat to national security.

The first witness for the prosecution was a national security officer who said Fahmy is a member of the Brotherhood. The defence team was not allowed to cross-examine witnesses Wednesday.

The trial marks the first time Egypt has prosecuted journalists on terrorism-related charges. It comes amid an extensive crackdown on some secular dissidents and Brotherhood supporters.

In a statement Wednesday, Qatar-based Al-Jazeera said it is disappointed with the court's adjournment, and that it is continually working for the team's release.

"The trial in Egypt is a trial of journalism itself, so we remain resolute in calling for freedom of speech, for the right for people to know, and for the immediate release of all of Al-Jazeera's journalists in detention in Egypt," said Al Anstey, managing director of Al-Jazeera English.

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.

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 has also noted that while consular staff in Cairo have been extremely helpful, officials have indicated the 40-year-old's dual citizenship limits how much they can do.