Tarek Loubani of London, Ont., and John Greyson of Toronto were arrested in Cairo on Aug. 16. They have yet to face formal charges.
Greyson's sister, Cecilia, and a friend of the Canadians, Justin Podur, released a statement on Monday that said the men had informed friends and supporters through their Egyptian lawyers of the decision to go on a hunger strike.
"They will be refusing food beginning September the 16th to protest the arbitrary nature of their detention by Egyptian authorities," the release said.
On Sunday, Podur told CBC News that Greyson and Loubani's "detention has been extended … for 15 days."
Loubani, a doctor, and Greyson, a filmmaker and university professor, had been intending to make their way to Gaza last month when they were arrested.
“We can only imagine the anguish that John and Tarek feel after realizing that their detention could be extended for so long in what can only be described as an arbitrary process that lacks any credibility,” Cecilia said on Monday.
Monday's release said it's believed the Canadians' detention could be extended up to two years without any charges being laid.
“We know that they did not take the decision to begin a hunger strike lightly, and we want them to know we will do everything we can to support them and get them home soon," Cecilia said.
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