A policewoman has died and a city employee is critical after a man wearing a bullet-proof vest fired on them with an automatic rifle outside Paris, police said.
The gunman is still on the run, said Interior Minister Bernard Cazeneuve - who rushed to the scene at Malakoff just south of Paris - contradicting information given earlier by a source close to the case, who said the suspect had been detained.
Meanwhile, an explosion was reported at a kebab shop near a mosque in eastern France. Officials say there were no casualties.
Today's firing incident comes a day after 12 people were killed by three gunmen in a deadly attack on satirical weekly Charlie Hebdo, but no link has yet been established between the two shootings.
The masked, black-clad gunmen burst into the offices of the Charlie Hebdo magazine on Wednesday morning, killing some of France's most outspoken journalists and two policemen, before jumping into a car and escaping.
The youngest of those gunmen surrendered earlier today at a police station. Seven people have been detained in the hunt for the other two accused, who are brothers. Authorities have warned that the two brothers are "armed and dangerous."
Prime Minister Manuel Valls meanwhile told RTL radio that the two suspects were known to intelligence services and were "no doubt" being followed before Wednesday's attack.
They have been identified as Cherif Kouachi, 32, a known jihadist convicted in 2008 for involvement in a network sending fighters to Iraq, and his 34-year-old brother Said. Both were born in Paris.
The massacre triggered an outpouring of solidarity around the world, with outraged people from Moscow to Washington rallying in their tens of thousands under the banner "I am Charlie", in support of press freedom and the controversial Charlie Hebdo magazine.