Two men arrested after trainee police officer who 'dreamed of serving her country' gunned down in second French shooting

Police have reportedly arrested two men in connection with a shooting south of Paris that left a female police officer dead.

Sources told AFP a 52-year-old man and one other person are in custody over the attack, that also left a city employee fighting for his life.

Clarissa Jean-Philippe, 27, was reportedly attending a traffic incident as a municipal police officer in Montrouge when she was gunned down just before 8am (6pm AEDT).

A street cleaner is in a serious condition after he tried to confront the gunman and was shot in the face.

France's top security official Bernard Cazenueve said Jean-Philippe "dreamed of serving her country" after moving to Paris from the island of Martinique.

The shooting occurred a day after a deadly attack on satirical weekly Charlie Hebdo but French security officials say it remains too early to draw any connection between the shootings.

It was "a scene of panic," said witness Ahmed Sassi, 38.

From his kitchen window, he said he saw "a police officer standing in the road. A man with dark clothes shot them at point blank range, while continuing to run."

The gunman was said to be carrying a bulletproof vest, a handgun and an automatic rifle.

The investigation is being handled by anti-terror judges, the prosecutor's office has announced.