People have said the worst things about us ... You can see by the way they look at you in the street, they think we're murderers

Roland Carde

September's blast killed 30 people and injured more than two thousand and it turned this huge petrochemical plant near Toulouse into a skeletal, rubble-strewn wasteland.

But it caused more than just physical damage - coming 10 days after the attacks in the United States, the explosion also exposed the uneasy relationship between local Muslims and Christians.

Roland Carde's brother-in-law Hassan Jandoubi was one of the factory workers who died.

A non-practising Muslim, Hassan was accused in the press of being an Islamic fundamentalist, who may have caused the explosion.

The proof - an alleged argument he had had about the American flag and the fact he was wearing several pairs of underwear; consistent, it was claimed, with the behaviour of suicide bombers.

An inquiry has shown that the explosion was a tragic accident, and the family is bitter at the way they have been treated.

We can't call our buildings mosques, because that would be too much of a shock for the local population

Rachid Bouhmadi

"It's been terrible," Roland says, "not only have we had to cope with a death in the family, but people have said the worst things about us.

"You can see by the way they look at you in the street, they think we're murderers".

Double life

In a small converted sports hut down the road, Rachid Bouhmadi changes out of the clothes of an economics lecturer and into those of an imam.

This thoroughly modern Muslim - who keeps work and religion separate - was also affected by the blast; the hut - his mosque - was accused of being a breeding ground for extremists.

Not that you would know it is a mosque. Even before September, the authorities here insisted it should be called a cultural centre, so as not to offend local sensibilities.

For Rachid, this was already proof of the limits of integration.

If you allow a community to have a place to worship you have no reason to hide it. I would strongly advise posters saying 'this is the way to the mosque'

Alain Billon, Interior Ministry official

"We can't call our buildings mosques, because that would be too much of a shock for the local population," he says.

"The French see Muslims among them, they shop with them, they may even be their neighbours. But when we put up a sign that says mosque on it, they see it as an invasion of their country."

France does not have an official figure for the number of practising Muslims, but it does have some official mosques - like this one in another suburb of Toulouse.

Integration setback

Even so, government officials working towards greater integration are shocked by Rachid Boumahdi's enforced discretion.

Alain Billon, an Interior ministry official, who is organising elections to France's first ever Muslim body is dismayed by such circumstances.

"I think this is very wrong. I think if you allow a community to have a place to worship you have no reason to hide it. I would even very strongly advise to have posters saying 'this is the way to the mosque' and so on."

This is the other part of the integration question. Although they belong to the largest Muslim population in Europe, France's disparate Islamic communities have not organised themselves into a council or parliament.

Representation is especially important here, since the country does not have a single MP from a Muslim or North African background.

'Gaining influence'

Still, Alain Billon is adamant that society is changing.

Local residents are angered by the devastation and the redundancies

"From one year to another, you can see how this community is gaining in influence and power. You see it in the way French people eat, the way they listen to music - and this will have an effect on the political situation."

But in Toulouse this is seen as a rather optimistic view.

Although the increased tension has not led to any serious disturbances, the events of last September - both at home and abroad - have reinforced divisions that were already there:

The ruins of the AZF factory have become emblematic of French security and environmental concerns - it has already been visited by two candidates for the forthcoming presidential election.

But for Muslims here it is the symbol of something else - the continuing question mark over their position in French society.