The family group, which includes a baby and other children, are believed to have left their home in Nice in late September.
The rally in the hometown of the hostage beheaded by Algerian Islamists, came as flags were lowered to halfmast across France in mourning.
Two people in Cannes and Nice arested after police seized 388 virtual currency units worth €200,000 euros in the first such operation in Europe.
The 16-year-old, who is now in police custody in France, headed to Syria to fight after telling his father he was going to a nightclub.
Pole Wojciech Janowski says he did not fully police and now denies having ordered the killing in May of 77-year-old Helene Pastor in Nice.
The right-wing mayor Christian Estrosi announced ban until end of tournament following riots after the last two Algerian games.
Wojciech Janowski is still being quizzed over murder of his mother-in-law Hélène Pastor; her daughter Sylvie has been freed without charge.
The son-in-law of wealthy property owner Hélène Pastor is also among those being questioned following her ambush murder in May in Nice.
In a case that has gripped France, Maurice Agnelet, 76, is given 20-year jail term in his third trial for killing of his mistress Agnes Le Roux.
No injuries or significant damage were reported as a result of the quake near Nice which had a magnitude of 5.0.
Maurice Agnelet was acquitted in 1985 of murdering Agnès Le Roux, then freed by European Court of Human Rights after 2007 conviction.
A coffee ordered with the phrase ‘bonjour, un café s’il vous plait’ will only cost €1.40, against €7 for just grunting 'un café' to staff at Nice café.
Interior minister Manuel Valls says justice must take its course after protests over detention of Stephan Turk, who killed a robber outside his shop.
President Hollande drawn into high-profile case which has seen many suporters backing actions of a man who could face life in prison for murder.
A million people on Facebook have backed Nice jeweller who is now under investigation for murder after shooting dead teenager who robbed him.