MEGAN THOMPSON: This port city of around 850-thousand is France's second largest, and one of its most diverse. Located on France's southern Mediterranean shore, Marseille is home to tens of thousands of immigrants from throughout Europe and more recently, North Africa.

By some estimates, the city is now 30 to 40 per cent Muslim — one of the highest concentrations of Muslims anywhere in this overwhelmingly catholic country. Always a melting pot, Marseille hasn't seen the riots or violence that have broken out in other parts of France in recent years.

But even before the January attacks in Paris that shook the nation…first at the satirical newspaper paper Charlie Hebdo, and then, at a kosher market….. Tensions in Marseilles between Muslims and non-Muslims had been rising.

CLAUDE DE GARAM: It's awfully complicated, all of this. With the arrival of the foreigners who have changed everything in the town of Marseille.

MEGAN THOMPSON: retired photographer Claude de Garam has lived in Marseille his entire life. He said he's felt things change over the years.

CLAUDE DE GARAM: Before, everyone knew each other. Even the first immigrants in Marseille – the Italians, Spanish, all of that – it all worked fine. Perhaps because it was the same religion. But what came after – it's a lot more complicated. Less integrated.

CLAUDE DE GARAM: The old Marseillais are annoyed to have people who come and bother them – in their hometown. Because we have our ways. And the new arrivals feel not well accepted and so you feel their hatred increasing. You can see it in the buses. There are fights – and that didn't happen before.

MEGAN THOMPSON: De Garam said he's not sure what the future holds.

CLAUDE DE GARAM: We don't know where we are going, but we can feel that it's not towards peace. There's a feeling of uneasiness.

AZIZ: Yes, there are problems of Islamaphobia. In my opinion, it's happening more and more.

MEGAN THOMPSON: As we traveled around Marseille, we spoke to many French Muslims who told us they've seen things change here, too. Like our taxi driver, Aziz, who was born in Marseille to Tunisian parents. We heard about French-born Muslims feeling like they were sometimes considered foreigners. We also heard complaints about job discrimination…and feeling singled out by politicians.

AZIZ: Every public official, whenever there's an election, their number one issue is Islam. But I just gave you a little tour and almost half the people who live here are Muslim. And I don't think you saw anything different from other neighborhoods. Everybody lives normally.

MEGAN THOMPSON: Aziz was showing us around a lower-income section of north Marseille. Outside a mosque after Friday prayers we met several men who were very suspicious of our camera. Medy, a French-born Muslim of Algerian descent, was the only one who'd talk. He explained many Muslims feel they're portrayed unfairly by the media.

MEDY: They are always trying to say Islam is terrorists. Every time with our religion. So it annoys me. They are not telling the truth.

NATHALIE BENSILLA: There are lot of verbal insults. The stares, people in the streets looking at me.

MEGAN THOMPSON: Nathalie Bensilla lives on the other side of Marseille. She was also born in France, the daughter of an Algerian immigrant. She converted to Islam in her early 20s and is now married to the imam of the mosque we visited. The mother of seven said once or twice a month she's ridiculed because she wears a headscarf. She also said she's been excluded from her children's school field trips, and back in 2012 she had a confrontation in a store.

NATHALIE BENSILLA: A woman tore into me, really insulted me. She said you've rejected our origin. Because she knew that I'm French, because I told her. She really insulted me with all these names. She almost hit me.

MEGAN THOMPSON: Bensilla said she reported the incident to the police, but nothing happened. According to a national Muslim advocacy group in France, after the Paris attacks, the number of Islamophobic acts across the country increased by 70%, compared to the same time period last year.

NATHALIE BENSILLA: It doesn't bother me. I ignore them. But, when you have your kids with you and someone insults you, it's degrading. And frankly when it happens on the street it's hard to justify it to the kids, they don't understand. My son, he says, when I'm big, I'm going to fight these people if they talk to you that way. And I say, you can't respond to aggression with aggression.

MEGAN THOMPSON: Why do you think people treat you this way?

NATHALIE BENSILLA: I really, I think it's fear of ‘the other.' And also lack of understanding of our religion. Also I think that Muslims don't make enough effort to reach out and to explain the fundamentals of our religion. That there is a lot of respect for others.

STÉPHANE RAVIER: I would like to remind people that France is a Christian country, with an identity, a culture.

MEGAN THOMPSON: Stéphane Ravier is the mayor of the poor northern section of Marseille that we visited. He's also a member of France's far-right party, the National Front.

Last year, he made history, becoming one of the first politicians from that party ever elected to the French senate. The National Front is known for tough talk on immigration, security and Islam… and its hard line on secularism, which has offended members of the Muslim community. Ravier once interrupted a Muslim wedding because the bride's face was covered – a violation of French law.

STÉPHANE RAVIER: We have an identity, but we also have laws. French law forbids to anyone to be entirely veiled. So, I have only applied the law. So I'm telling the French Muslims and the Muslims in general you have a right to live your religion, but don't forget that here it is French soil, and in France, as it is done around the world, we also have to respect religions and rituals, customs, codes. So there is Islam and there is Islamism, which is growing

MEGAN THOMPSON: Even before the terror attacks in Paris, the National Front was gaining ground in France amidst growing concerns about the economy and security. French officials have estimated more than 1,000 people have left, or plan to leave France, to wage jihad in Syria and Iraq.

STÉPHANE RAVIER: Massive immigration is causing Islamization. We can see that there are some extremist elements at the heart. They are very active. And the French authorities are completely frozen because they fear being labeled Islamophobic. These small groups of Islamists within the heart of Islam are very active and those are the ones that I want to “fight.”

MEGAN THOMPSON: Since the attacks, the popularity of the National Front has grown even more. The party's leader came in first in a recent poll of potential candidates in the 2017 presidential election. We recently caught up with Ambroise Bouleis, a television journalist in Marseille, who said it's a surprising development for a party once considered fringe.

AMBROISE BOULEIS: They are doing very well. And part of the explanation might be that the attacks brought back, on the scene, their favorite topics. Immigration, national security. Those are the core of their political program.

MEGAN THOMPSON: As for the climate in Marseille after the attacks, Bouleis said, initially it was quite tense. But he told us the public response was more tepid here than in other major French cities, where hundreds of thousands marched in the streets. Bouleis explained that while many Muslims condemned the violence, they were also offended by the cartoons of Mohammad published in the paper Charlie Hebdo.

AMBROISE BOULEIS: Many of them decided not to go out, decided not to participate in this public grief. They decided not to say, ‘I am Charlie,” like everyone said this day. But some of them chose to say, “I am not Charlie.' Because for them, supporting Charlie Hebdo was supporting the caricatures of Mohammad that the satirical journal had published.

Many Muslims have felt stigmatized as well. Because the three terrorists called themselves Islam defenders. So it led some people to conflate in a way, Islam and terrorism. And there were some very racist rants on the Internet. So, a large part of the Muslim community was very deeply hurt.

MEGAN THOMPSON: It's all been a blow to an already-tense situation in Marseille. As for the future? Even before the attacks, there seemed to be little optimism:

CLAUDE DE GARAM: I think that we'll need a few generations to get used to it. Me, I won't be here. But my kids, I think they will be experiencing some tough moments.

NATHALIE BENSILLA: It's getting worse and worse. And frankly, I don't think it's going to get better. I don't think it's going to get better.