French cable television channel Canal+ said Friday that two French journalists working for the station in Egypt had been missing for more than 24 hours, dpa reported.
Canal+ said the two journalists were detained by armed men in Cairo on Thursday, along with several human rights workers, including a representative of Amnesty International and another person working for New York-based Human Rights Watch.
The station had no news of the journalists since.
Amnesty on Thursday had already confirmed that its French employee had been detained.
France's foreign ministry said it knew of two journalists who were still in detention - one from Figaro newspaper, and one from Magneto Presse, a television production company.
It was not clear whether the Magneto Presse employee was working for Canal+.
A number of Western journalists were detained, physically attacked or had their equipment seized or damaged Thursday in Cairo.
A Swedish television correspondent was hospitalized on Thursday after being seriously injured in a stabbing.
The attacks appeared to be mainly the work of supporters of President Hosny Mubarak, who accuse Western media of inciting mass demonstrations against his rule.