Protesters from ''6th of April'' group and other opposition activists chant slogans on bicycles as they take part in what they dub a "Freedom marathon'', calling for the release of activists in detention, in central CairoA protester from the ''6th of April'' group runs with other opposition activists as they take part in what they dub a "Freedom marathon'', calling for the release of activists in detention, in central CairoProtesters from the ''6th of April'' group and other opposition activists chant slogans after taking part in what they dub a "Freedom marathon'', calling for the release of activists in detention, in front of the press syndicate in CairoProtesters from ''6th of April'' group and other opposition activists chant slogans after taking part in what they dub a "Freedom marathon'', calling for the release of activists in detention, in central Cairo