An elderly woman has died after an armed man burst into a retirement home for monks near Montpellier in southern France.

The victim was stabbed and found bound and gagged outside the home, a spokesperson for the French Gendarmerie said.

The man who broke into the Chenes Verts retirement home in Montferrier-sur-Lez was reportedly armed with a knife and a sawn-off shotgun.

French police have arrested a 47-year-old former soldier who investigators said was the main suspect.

The suspect, who had served in France’s parachute regiment, worked at the missionaries’ home “some years ago” but was now unemployed, a source in the investigation told AFP.

He was arrested in the town where he lives, 15 kilometres from Montferrier-sur-Lez where the retirement home is located, and did not put up any resistance.

There is no indication the attack is terror-related, sources close to the investigation said.

More than 100 police officers were dispatched to the facility, which is home to around 70 men and women who have served as missionaries in Africa.

Armed police conducted room-to-room searches of the building, Le Parisien reports.

After completing a search of the ground floor, officers took 59 monks into safety one by one, local media says.

Reuters reports that the woman was a resident of the home, but BFMTV says that she was a warden.

Earlier reports suggested that a man had also died at the home, but this has not been confirmed.

"For the time being, there is only one victim," Montpellier prosecutor Christophe Barret told AFP.

"There is no particular evidence about the motive for this crime."

Authorities have described the incident as a "criminal act".

Montferrier-sur-Luz Mayor Michel Fraysse said: "A large number of security forces, firefighters and ambulance personnel are at the scene."

Some of the home's residents are more than 90-years-old, local councillor Alain Berthet said.

Olivier Ribadeau Dumas, the secretary general of the French Bishops' Conference, tweeted: "Our prayers tonight go to the woman who lost her life in this attack on a retirement home."

France remains under a state of emergency since a series of terrorist attacks last year.