French police on Sunday shot and wounded a psychiatric patient suspected of killing his mother, chopping off her right leg and throwing it into the street, police said.

Armed response officers opened fire on the man after he shot at them, police said.

The suspect, aged around 30, needed hospital treatment for a wound to the abdomen but his life was not in danger.

Police were initially called to the woman's home in Lormont, near the southwestern city of Bordeaux, after a human leg was found lying on the street.

Police later identified it as that of the suspect's 56-year-old mother, whose body was found inside her flat.

The suspect was on home leave from the nearby Cadillac psychiatric hospital where he is an in-patient.