But he said that, apart from the policeman killed on the spot by the attacker, two police officers had been seriously wounded.
"An automatic weapon was used against police, a weapon of war," the spokesman, Pierre-Henry Brandet, told reporters, adding that the "terrorist threat" in the country remained high.
Brandet said the shooting started at shortly after 9 p.m. when a car stopped alongside a stationary police car. "A man immediately got out and opened fire on the police car, fatally wounding a police officer ... He also wounded a second one, it would seem very seriously," he said.
The identity of the attacker, who was killed, had not yet been definitely established, he said.