A rally of defiance and sorrow, protected by an unparalleled level of security, on Sunday will honor the 17 victims of three days of bloodshed in Paris that left France on alert for more violence.

Key members of the French government will meet Saturday morning to decide on new measures aimed at thwarting a repeat of the attacks in Paris that culminated in a massacre of 12 people at a satirical newspaper, and a supermarket bloodbath that left four hostages dead.

French security forces struggled with two rapidly developing hostage-taking situations Friday, one northeast of Paris where two terror suspects were holed up with a hostage in a printing plant and the other an attack on a kosher market in Paris involving at least five hostages.