Hollande says Mali Intervention Has 'Stopped' Islamists

France has ordered tightened security, including anti-terrorist measures, following its military intervention against Islamists in Mali and Somalia, President Francois Hollande said Saturday.

Hollande said France "has to take all necessary precautions" in the face of a terrorist threat, including "surveillance of our public buildings and our transport network."

The French leader evoked Vigipirate, France's national security alert system, created in 1978 and updated three times.

The system defines four levels of threats represented by five colors: white, yellow, orange, red and scarlet.

The levels call for specific security measures, including increased police or police-military mixed patrols in subways, train stations and other vulnerable locations.

The highest level scarlet includes measures that are highly disruptive to public life.

France on Friday launched air raids to support Malian ground troops fighting to wrest back the key town of Konna from Islamist rebels holding the west African country's vast desert north.

The offensive left dozens dead.