Burning cars and bullets: Who is attacking French prisons?

What's the latest?

President Emmanuel Macron vowed the attackers would be "found, tried and punished" after days of incidents around French jails, with one sprayed with automatic gunfire.

Anti-terrorism investigators are leading the inquiry into the attacks that Macron said were an attempt to "intimidate our prison staff and attack facilities with unacceptable violence".

Justice Minister Gerald Darmanin accused the drug trafficking underworld of being responsible. "Clearly people are trying to destabilise the state by intimidating it," he told French media.

Police accompanied some prison staff when they went to penitentiaries on Wednesday.

More than 20 vehicles have now been set ablaze or been the targets of vandalism in the campaign since Sunday.

Early Wednesday, assailants set fire to three vehicles in the car park of a jail in the southern town of Tarascon, its prosecutor said.

The car of another guard from a jail outside the southern city of Aix-en-Provence was torched outside his home, a representative of the prison workers' union said.

In the Paris region, assailants tried to start a fire in the entrance of a building where a woman prison guard lives, a police source said. The letters "DDPF" -- standing for "Rights of French Prisoners" -- were sprayed on the building as they have at other jails this week.

So who's behind the attacks?

Darmanin said there could be a link to his plan to lock up 200 of France's 700 most dangerous drug traffickers in two top-security prisons. Parliament is also to vote this month on a bill against drug-related crime.

A probe is underway into the attacks since Sunday, but Darmanin has accused people linked to drug trafficking.

"They are doing it because we are taking measures against the permissiveness that existed until now in jails," he said.

Darmanin and Interior Minister Bruno Retailleau have in recent months vowed to intensify the fight against narcotics and drug-related crime.

Darmanin said he was seeking to crack down on "drug networks that continue to operate from prison cells.

"They order killings, launder money. They threaten police officers, judges, prison guards, and they escape," he said.

Darmanin is leading what he calls a "prison revolution" that aims to lock up 200 of France's 700 most dangerous drug traffickers in two top-security prisons from this summer.

"We won't back down because they threaten the state," said Darmanin. "Because if the state gives in there's nothing left to protect the French people."

French prison guards in fear

Several prison guards, who did not give their names out of fear for their safety, said they were worried.

"It's the first time in my career that I look back as I leave work and check what is going on in the parking lot," a 47-year-old woman, who has worked as a prison guard for 22 years, told AFP.

She said she now locks the door as soon as she gets home.

Another, 34, called the events "scary".

"Tracking down a guard, following them home requires preparation and premeditation," he said.

A woman guard in Marseille told how the families of inmates film guards and their cars with mobile phones. "They do what they want, with no impunity," the 45-year-old said.

"Threats and intimidation inside prisons are part of the daily grind," the secretary-general of the UFAP UNSA Justice union, Wilfried Fonck, told AFP.

"But that this is now happening outside is worrying."

Dominique Gombert, deputy head of the FO Justice union, spoke of "a desire to spread terror".