Police have launched a manhunt in the suburbs of Marseille after gunmen opened fire on the chief of police of the city in southern France.Masked gunmen armed with Kalashnikov rifles attacked a car carrying Pierre-Marie Bourniquel, the director of the Marseilles police, in the district of La Castellane northern Marseille, according to French media reports on Monday.Bourniquel was left uninjured but reportedly managed to leave the vehicle and take cover.He later told French TV BFMTV that was not clear yet if he was the target of the attack or was caught in a shooting between two rival gangs.A police source told daily newspaper Le Figaro that the shooting could have been a dispute between drug traffickers."The drug trade in Marseille - cannabis and cocaine in particular - can bring in more than 100,000 eruos a month, just for a single city," the newspaper reported. The shooting came hours before Prime Minister Manuel Valls was due to pay his first visit to the city since he came to office. Helicopters and police officers were deployed to search the area for the gunmen, who fled the scene after the attack.A major center of trade and industry and capital of the southern Provence-Alpes-Côte d'Azur region, Marseille is France's largest city on the Mediterranean coast and boasts the country's largest commercial port.