Assailants targeted cars and a building lobby linked to prison staff in France overnight, the authorities said, the latest in a series of such attacks.
Since Sunday, unknown assailants have hit several jails and facilities across France, torching cars, spraying the entrance of one prison with automatic fire, and leaving mysterious inscriptions.
The national anti-terrorist prosecutor's office is leading a probe into the attacks, and Justice Minister Gerald Darmanin accused people linked to drug trafficking of being responsible.
"Clearly people are trying to de stabilise the state by intimidating it," he told the CNews/Europe 1 broadcaster on Wednesday morning.
"They are doing it because we are taking measures against the permissiveness that has 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 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.
A law against drug-related crime, which includes these prisons, is set to go to a vote in parliament at the end of the month.
Raduano had been serving a 24-year prison sentence for membership of a criminal organisation, drug trafficking, holding illegal weapons and other crimes, according to Europol.
'Fundamental rights'
Early on Wednesday, assailants set fire to three cars — including one belonging to a prison guard — in the car park of a jail in the southern town of Tarascon, its prosecutor said.
The car of another guard working at a jail outside Aix-en-Provence, also in the south, was torched outside his home, a representative from a prison worker union said.
In the Seine-et-Marne region near Paris, someone scrawled the letters "DDPF" — standing for "Rights of French Prisoners" — and tried to start a fire in the entrance of a building where a woman prison guard lives, a police source said.
Before that, up until late on Tuesday, 21 vehicles had been graffitied and or set on fire, a police source said.
Most of the incidents — largely torched cars but also automatic rifle volleys fired at a prison entrance near the southern city of Toulon — were recorded overnight Monday to Tuesday.
The inscription "DDPF" featured at nearly all sites, except for the prison near Toulon where assailants left the mysteri ous acronym "DDFM".
A group calling itself "DDPF" on Telegram on Wednesday published a video showing a prison guard leaving a car, then shaky footage of a letter box, zooming in on the name on it.
The video, viewed by AFP before it was deleted, ends with the letters "DDPF" against the backdrop of a car burning in front of a building at night. The account, created on Saturday, has more than 1,000 followers.
In a post on Sunday, the group described itself as "a movement dedicated to denouncing violations of fundamental rights that minister Gerald Darmanin intends to breach".
Darmanin told CNews 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 added.
Assailants last year attacked a prison van carrying suspected drugs baron Mohamed Amra at a highway tollbooth, freeing him and killing two prison guards.
He has since been re-arrested in Romania and extradited back to France, where he is being held at one of the two future high-security prisons.
The International Prisons Observatory watchdog has criticised Darmanin's plan, saying it was based on a "security obsession" and included measures violating "human rights".
A French court ordered prison terms for eight suspects charged in the 2016 terror attack, where an attacker ploughed his truck into a crowd celebrating a national holiday.
