Crack police units and other security forces fanned out across the country to quell violence over the shooting, which took place during a traffic stop in a Paris suburb on Tuesday.
Despite the security presence, looting took place on Friday night in the cities of Lyon, Marseille and Grenoble with bands of often hooded rioters pillaging shops.
Protesters also set fire to cars and trash bins.
There was daylight looting Friday in the eastern city of Strasbourg, where rioters targeted an Apple Store and other shops.
Police used teargas in the southern city of Marseille after youths threw projectiles at police vehicles in the Vieux-Port district, which is popular with tourists.
Marseille mayor Benoit Payan called for troop reinforcements saying the "scenes of looting and violence are unacceptable".
Eighty people were arrested in Marseille among the 270 nationwide Friday, Interior Minister Gerald Darmanin said.
French President Emmanuel Macron, after rushing back from an EU summit to chair a crisis meeting, denounced the "unacceptable exploitation of a death of an adolescent" in some quarters.