 However, some 600 managed to escape and join the FLN with weapons and equipment.Late in 1957, General Raoul Salan, commanding the French Army in Algeria, instituted a system of "quadrillage" (surveillance using a grid pattern), dividing the country into sectors, each permanently garrisoned by troops responsible for suppressing rebel operations in their assigned territory.Salan's methods sharply reduced the instances of FLN terrorism but tied down a large number of troops in static defense.