World leaders to attend massive ‘unity rally’ in France

French officials announced “exceptional measures” to protect not only the throngs expected to gather near the Place de la Republique in central Paris, but also a veritable who’s who of foreign leaders that will test security forces of a nation rocked by days of terrorist violence.

The massive 3 p.m. (9 a.m. ET) rally comes as French law enforcement officers are being told to erase their social media presence and to carry their weapons at all times because terror sleeper cells have been activated over the last 24 hours in the country, a French police source who attended a briefing Saturday told CNN terror analyst Samuel Laurent.

Brothers Cherif and Said Kouachi, authors of Wednesday’s deadly attack on the office of satirical magazine Charlie Hebdo, were killed Friday after the two violent standoffs. The brothers are suspected of killing 12 people in slaughter at the magazine offices.

Coulibaly, suspected in the slaying of a police officer, was killed by security forces Friday after he shot and killed four hostages during a siege at the kosher market.

CNN