CAIRO — A private Egyptian television channel has aired what it called exclusive footage of the arrest and interrogation of two foreign journalists, who are now being held in a high-security prison awaiting trial on terrorism-related charges.

The 22-minute video, broadcast Sunday night by the satellite channel al-Tahrir, appeared to have been taken by police forces on Dec. 29 as they stormed a pair of hotel rooms that the Qatar-owned Al Jazeera English satellite network was using as temporary offices. Among those detained were Egyptian-Canadian Mohamed Fadel Fahmy and Australian Peter Greste, who stand accused of conspiring with “terrorists” to fabricate news about Egypt.

Al Jazeera denounced the video in a statement Monday, describing it as an attempt to demonize its journalists and saying it could prejudice their trial.

Egypt’s military-backed government has been waging an increasinglyheavy-handed crackdown on dissent nationwide since it came to power through a July 3 coup.

On Monday, the military said it launched a major offensive in the northern Sinai Peninsula, killing at least 20 people, the Associated Press reported. Bedouin residents of North Sinai said the announcement was mostly bluster, meant to bolster public sympathy for the military. Clashes erupted after the military demolished a cluster of homes, but “there were no deaths on either side,” said one powerful local tribal leader known as Abu Ashraf.

A Sinai-based extremist group has claimed responsibility for a series of recent attacks on police and military targets, including deadly bombings in the capital. Protesters have also clashed regularly with police across the country.

Egyptian security forces and local media have cast the country’s internal struggle as a “war on terrorism,” using the term to justify the arrest and prosecution of thousands of Egyptians, including Islamists, liberal activists and journalists.

Al Jazeera’s Arabic and English sister channels have landed at the center of the government’s crackdown on media; both networks have been blasted as mouthpieces for the Muslim Brotherhood, which forged close ties with Qatar during its brief time in power. The government formally branded the Brotherhood a “terrorist organization” in December. Egyptian media, both state-owned and private, have helped push the government’s narrative.

Egypt’s public prosecutor last week moved to charge 20 people — including the two journalists arrested in the video — with manipulating clips to assist the “terrorists” in falsely depicting Egypt as a country in the midst of a civil war.

“When was the last time you went to Qatar?” an off-camera interrogator asks Fahmy and Greste in the video. “So you conduct an interview, and then they send you money?” he says in questioning Fahmy, who responds by explaining calmly how a salary works.

Both men have been detained, along with cameraman Baher Mohamed, who was arrested at home, for more than a month. Fahmy’s family says he is being held in solitary confinement.

The release of the footage — theatrically set to the soundtrack of the sci-fi action movie “Thor: The Dark World” — appeared designed to bolster public sympathy for the prosecution. During the interrogation, the cameraman zooms in on items — including Apple laptops, external hard drives and even Greste’s business card — that supposedly implicate the network and its journalists in a conspiracy.