Paris attacks show problem of radicalism

Two of the gunmen who were involved in the Paris attacks are believed to have been radicalised in prison, authorities say.

Two of the gunmen involved in the Paris attacks are believed to have been radicalised in prison. (AAP)

At least two of the gunmen who unleashed terror on France are believed to have been radicalised in prison, a fertile ground for extremism that authorities are struggling to contain.

Both Mohamed Merah, the Al-Qaeda militant who shot dead seven people in a series of 2012 attacks, and Mehdi Nemmouche, last year's Brussels Jewish museum killer, were radicalised in jail.

And in the latest attacks, Cherif Kouachi, one of the brothers who massacred 12 people in an attack on the Charlie Hebdo magazine, came under the influence of Djamel Beghal, a known figure of French radical Islamism, when serving time in the Fleury-Merogis prison.

Amedy Coulibaly, the man who killed a policewoman and four shoppers, also came under Beghal's influence and met Kouachi in the same jail, Europe's largest.

"We have a real problem with our prison policy," said Martin Pradel, a lawyer who has defended jihadists.

"Promiscuity, idleness and a lack of psychological support is all fertile ground for radical practices to bloom."

The justice ministry, while acknowledging the problem, says it is not quite as dire as believed.

"Of the 152 people currently jailed in France (out of 67,000 prisoners) as part of terrorist cases, just 16 per cent of them had already served time in prison, 84 per cent therefore radicalised elsewhere," said ministry spokesman Pierre Rance.

And among the 152, "around 60 have been identified as preachers engaged in proselytism among other Muslim detainees," he added.

The justice ministry also aims to fight against Islamist proselytism by increasing the number of mainstream Muslim chaplains in prisons.

One chaplain said that in the absence of legitimate preachers, detainees seeking spiritual guidance will seek out other prisoners who may mislead them.

"As by nature people hate emptiness and there are not enough chaplains, detainees who have a spiritual need go to inmates who practice (religion) ...," Yaniss Warrach, a chaplain at the Alencon-Conde prison in northwestern France, said.

The ministry says it has created 32 such posts since 2012.