Egyptian news sources say a judge has ordered the two Canadians, along with seven other foreign nationals, held for 15 days pending an investigation by prosecutors.
Toronto filmmaker John Greyson and London, Ont., doctor Tarek Loubani were arrested by Egyptian police Friday when they were in Cairo on their way to Gaza.
“We were disappointed to learn today that Dr. Loubani and Mr. Greyson will continue to be held in detention," minister of state for foreign affairs Lynne Yelich said in a statement Tuesday after she and Foreign Affairs Minister John Baird spoke with Egypt's ambassador to Canada.
“The government of Canada is deeply disappointed by this decision as there continues to be a lack of evidence."
Family members have hired a Cairo lawyer to represent the two men, although it remained unclear whether the lawyer would be able to aid in securing an earlier release.
The ONA news agency says Greyson and Loubani are among dozens accused of being involved with the Muslim Brotherhood, and of trying to storm a police station in Cairo's Ramses Square.
Justin Podur, a friend of the two detained Canadians, called the allegations "far-fetched."
He noted that four of the foreign nationals, all from Ireland, were arrested on Saturday, Aug. 17, when police raided the al-Fateh mosque.
"Tarek and John were already in custody at the time," Podur said in a statement.
The Al-Youm Al-Sabea newspaper says the Canadians are being held along with the four Irish nationals, two Syrians and one person from Turkey.
Citing a prosecutor's release, the newspaper says the nine face a range of serious accusations, including belonging to an armed gang, threatening security and social peace, disabling public transport and communications and possession of firearms, ammunition and explosives.
The Turkish national, reportedly photojournalist Metin Turan with the Turkish Radio and Television Corporation, was detained on Aug. 14, said Podur, although Reporters Without Borders said he was detained Aug. 16 while covering the al-Fateh raid.
The two Canadians arrived in Cairo on Aug. 15, said Podur, and were arrested a short time later.
"The prosecution's press release is a clear attempt to put a group of foreigners arrested at different times and places into a single group to create a far-fetched story about foreigners to justify ongoing imprisonment," he said.
"No allegations against John and Tarek have been relayed through consular officials or their Egyptian counsel. We continue to demand nothing short of their immediate release."
The Harper government says it is doing everything it can to get the men released and to learn more about the charges that they face.
"The Egyptian ambassador has committed to press for a timely and positive resolution to this matter," said Yelich. "Canada will continue to engage with the highest levels until this matter is resolved."
Prime Minister Stephen Harper said Monday he was "extremely concerned" about the safety of the two Canadians.
The Irish Times reported Tuesday that the Irish embassy in Cairo was granted consular access to four siblings who were among those detained after security forces stormed the al-Fateh mosque, which became the focus of the latest episode in a bloody showdown between Egypt’s military-installed government and the Muslim Brotherhood.
The four Irish nationals had reportedly taken refuge in the mosque after taking part in demonstrations against the ouster of Egyptian President Mohamed Morsi.
However Yelich said it appeared the Canadians were simply "two people ... in the wrong place at the wrong time."
About 900 people have been killed, including 100 police and soldiers, after authorities broke up Muslim Brotherhood protest camps in Cairo almost a week ago.
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