Senior police officials and elected leaders held a meeting Saturday morning in Marseille to discuss the situation, Radio France Internationale reported.
Investigators believe at least 15 killings in the city this year are gang-related.
The most recent victim, Adrien Anigo, the son of the president of the soccer club Olympique Marseille, died Thursday.
Officials said that in addition to sending more police officers to Marseille they discussed educational measures and other steps to reduce violence.
Members of the "June First Collective," a group of women who have lost children to violence, said putting more police on the streets is not enough.
"Drug trafficking is not going to be eradicated by sending in more police," the group said in a statement, adding they hope to see dialogue between groups like theirs and "powerful public figures."