A fireman of Algerian origin, Faisal helped evacuate thousands from the Stade de France during the Paris attacks, guiding panicked football fans to safety as suicide bombers blew themselves up outside.

Now he fears the November 13 massacre across the French capital will deepen a dangerous "them and us" schism between France's five-million-strong Muslim population and the rest of society.

The jihadists behind the attacks appear to be Europeans of Arab origin, and the 40-year-old fireman worries that French Muslims may suffer greater discrimination as a result.

"If you have a Muslim name, they stop seeing you as a French person and they start to see you as an Arab, a potential terrorist," Faisal said.

The attacks will also exacerbate an existing problem, he fears -- that many Muslims don't feel part of France, and even resent it.

And that resentment is precisely what the Islamic State group seeks to exploit.

Like others around Boulevard Barbes, a bustling microcosm of Paris' second and third-generation ethnic communities, Faisal condemned the attacks outright.

"I was working inside the Stade de France Friday night when we got the call on the radio to evacuate everyone. But when this kind of attack happens, it deepens the separation between us and the rest of society," the fireman said.

A French soldier stands guard in front of the Grande Mosque, on November 20, 2015 in Strasbourg, eastern France Patrick Hertzog, AFP

France's Muslim community -- the largest in Europe -- is as diverse as the country itself.

But there are many who voice anxiety about their place in a country with a bloody colonial history in North Africa and a commitment to secularism that some see as contradictory with Islamic traditions.

This anxiety spiked as politicians such as ex-prime minister Alain Juppe calling on Muslims to publicly "say they have nothing to do with this barbarism".

"Muslims do not have to justify themselves... Are they guilty by association?" responded an opinion piece writer, Hatem Nafti, in left-leaning daily Liberation.

- Alienation -

French-born Mohammad, a 30-year-old Algerian CD and DVD shop owner in Barbes, and his friend Samir did some painful soul-searching.

"The problem is with how they treated immigrants to begin with (40-50 years ago). They put the Arabs in (sprawling suburban areas) far from everyone else," Mohammad said, nervously puffing at a Marlboro cigarette.

Decades after the first major waves of migration in the 1960s, many thousands of people still live in low-cost housing projects in Paris' downtrodden banlieue (suburbs), where petty crime is rife and life is completely different from the glittering city centre.

People pray at a mosque on November 20, 2015 in La Courneuve, near Paris Dominique Faget, AFP

Jobs are harder to come by, with unemployment estimated in 2013 at 23 percent in contrast with nine percent elsewhere in the city.

The suburbs -— and also parts of the 18th district, where Barbes is located -— saw major riots in 2005 that emphasised the alienation.

It is this feeling of disenfranchisement that can be exploited by IS, warn researchers, with people on the fringes drawn to a movement that can give misguided aims to directionless youth.

- 'Dis-integration' -

Didier Lapeyronnie, who teaches sociology at Paris' La Sorbonne university, said many French Muslims "do not feel like they are part of the national community".

And for a tiny minority, jihadism can be used to build an alternative worldview.

"Terrorism is not necessarily linked to marginalisation," Lapeyronnie said, adding however that "in some areas... a counter-culture, a counter-society has been created, and Islam is used to construct a worldview."

"There is a political failure of the integration model... a process of dis-integration," he said.

A French soldier stands guard in front of the Great Mosque during Friday prayers on November 20, 2015 in Strasbourg Patrick Hertzog, AFP

Paris-based expert Karim Bitar says IS takes full advantage of this.

The group "has a well-honed dual strategy of tapping into feelings of humiliation of Sunnis in Iraq and Syria and simultaneously exploiting the alienation of disenfranchised Muslim youth in Europe," he told AFP.

Some 1,000 French men and women have joined IS in Iraq and Syria.

The group has "everything to gain from recruiting French youth: they improve their operational capabilities considerably and they psychologically score a victory by sharpening the contradictions within Western societies," said Bitar of the Institute for International and Strategic Affairs.

- 'In it for the adrenalin' -

European recruits do not necessarily know much about Islam at all, nor are they necessarily seeking to escape a life of want.

Two of the Paris attackers, Brahim and Salah Abdelslam, ran a bar in Belgium which was shut down because of reports that customers smoked marijuana there.

Jihadist recruits "are often in it for the adrenalin, the adventure, the excitement and to escape their existential malaise," Bitar said.

Wearing his hair close-shaven and a black leather jacket, Samir in the Barbes music shop agreed.

"They (the jihadists) recruit people with criminal records online to do their dirty work, offering them protection," said Samir, a security guard, as electronic Algerian pop boomed in the background.

"It hurts that they don't see the difference between me and the terrorists."