One month on since the attacks on the French satirical weekly Charlie Hebdo and a kosher supermarket, they are nervous that a uniformed actor donning fake weapons for an action flick could either be seen as a target or scare the public.
Police have already received calls from nervous passers-by who spotted men with Kalashnikovs in a restaurant.
They turned out to be actors filming a scene and, since the premises were private, they did not need permission to do so.
Paris’s police authorities say the measure is only temporary and that filming applications are still being authorised on a case-by-case basis.
However, films featuring fake arms, explosives and actors in police or military uniforms will be banned from shooting outdoors.
Productions using religious or school backdrops in the French capital could also be affected.