Around 20 prisons were blocked across the country on Wednesday morning after unions representing guards called for action.

Protesting prison guards set fire to tyres and built barricades in front of the entrances to the establishments.

They vowed the no staff or visitors would gain access to the prisons as they protested to raise the alarm at the dangers they face on daily basis due to the number of radicalised prisoners.

“Colleagues want to go to work but we do not abandon them, we do not send them to die,” a local union leader at the Fleury-Merogis prison outside Paris, Thibault Capelle, told AFP.

The action follows Tuesday's incident when a “radicalised” inmate at a prison in northwest France seriously wounded two guards in a knife attack. 

He was later shot and injured in a police raid that also left his visiting partner fatally wounded.

Prisoner Michael Chiolo and his female partner had been holed up in the family-visiting area of the modern, high-security prison at Conde-sur-Sarthe 
in Normandy when police moved in and detained them, Interior Minister Christophe Castaner said on Twitter.

Both were shot and wounded in the operation and “the woman died” of her injuries, a source close to the case said, adding that Chiolo was less seriously wounded in the cheek.

Elite police units moved in some 10 hours after 27-year-old Chiolo wounded the prison guards with a knife which Justice Minister Nicole Belloubet suggested might have been smuggled into the prison by his partner.

“There is no doubt as to the terrorist nature of this attack,” Belloubet told reporters earlier.

Chiolo, who was serving a 30-year sentence, is thought to have become a “radicalised” Islamist while in prison.

He shouted “Allahu Akhbar” (God is Greatest) during his rampage in the family-visiting area, prison staff representative Alassanne Sall told AFP.

The latest violence comes as prison staff nationwide, who have been demanding better working conditions, have repeatedly staged protests on Tuesdays.

(AFP)

In January 2018, prison staff held three weeks of protests after a guard was attacked by a jihadist inmate at a high-security jail in northern France.

Experts and trade unions have consistently raised the alarm about the spread of extremism in French prisons, leading the government to build special facilities to house dangerous individuals who are sometimes held in solitary confinement.

The Conde-sur-Sarthe prison is one of France's most secure jails and does not suffer from overcrowding, unlike other facilities, according to Belloubet.

But despite having been identified as an extremist, Chiolo was not housed in a secure wing for radicalised inmates which was opened in September, she added.

The first “jihadist attack” launched from within a prison in France took place in September 2016, according to prison authorities.

A Moroccan, jailed for attempting to travel to Syria to join jihadists, attacked two guards with a knife at a prison in Osny, northwest of Paris, saying he was acting on behalf of the Islamic State.

Then in January 2018, a German Islamist extremist, Christian Ganczarski, jailed for helping organise an attack against a synagogue in Djerba, Tunisia, wounded three prison guards in a knife attack at Vendin-le-Vieil, northern France, prompting staff to demand better safety and working conditions.