actually, what is surely known about those three youths in the transformator yard (yes, three ... one got away severly injured, the other two were killed) is that they attened a soccer match and at about the time they hid in the transformator yard, a blackout was registered in exactly this transformator's surrounding areas. Everything else are pure speculations at this time.
What, in my opionion comes closest to what probably happened is that they left the stadium together with a crowd of other adolescents when some began to run because they've spotted some cops doing identity checks [french cops are known to be racist, check the amnesty report on France:
http://web.amnesty.org/report2005/fra-summary-eng] - that's not even stupid, running from the cops will probably save you some hours of waiting for nothing in the police station and sometimes from being violated if you're non-white in the Paris' suburbs. Climbing over a secured wall is just as smart: Most cops are too lazy to climb anything if they're not sure what they're going to catch. And if it's just a young guy or two who didn't do anything - why bother?
(the official account is that those 3 boys had broken into "private property" and tried to hide on the transformator yard; the third version is that the crowd who left the stadium began running - and noone knows exactly why they did that...)
In the night from thursday to friday, the first militant actions were performed in Clichy-sous-Bois (the suburb with the transformator yard);
in the following two nights the clashes spread to Montfermeil, a neighboring suburb.
On Sunday evening a a tear gas grenade detonated in a mosque filled with about 200 muslims - and once again this led to two different stories from the police:
In the first version, a police commission declared that the tear gas-grenade was fired from a gun and did not have a stable flight path but it did not detonate inside the mosque but in front of its door. This story was later [monday morning] updated and now contains the information that a cop from another part of Paris shot the grenade at a group of "highly mobile young people" and did not know that there was a mosque next to this group.
The other version is that the grenade was not a tear gas-grenade but a pepper spray-grenade, which are not being used by any police departments in and around Paris.
As the french police is not known to be friendly to foreigners, many people believe that the grenade was shot into the mosque on purpose.
I assume that it was in fact a tear gas-grenade (hey, the story got an update after another part of the police department claimed that there was no police involved in this incident) which detonated inside the mosque - but I'm not sure if it was on purpose or an accident.
well, whatever the real story is: This incident definitely did not help to stop the violence...
by the way, during the last couple of nights there were some burning cars in Berlin, Bremen and Frankfurt [all in Germany] as well.
(I tried to report what is known about the events triggering the riots as factual as possible; as long as there's no "I believe" or something like that in a sentence this is based on several german newspapers and the "racist police" is not an assumption but based on information gathered by amnesty international throughout many years)
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here's my opinion which is mostly not based on anything but my own interpretations - be more careful with the following statements than with the statements above:
These riots are nothing which has been organised on a long-term basis but a somewhat sudden explosion of anger and frustration since most of the people participating in the riots are pretty young - but somewhat backed by their older neighbors, there have been reports about people cheering for them through open windows and several newspapers quoted people who think that violence is not the way they'd have handled things but they know exactly how "they" feel.
I fear that european right wing parties can use these riots during the next election campaigns as a reason why aliens should be kicked out of Europe [or, when they don't accept the European Union, the countries they're in]. Those riots did not occur due to the violent nature of african people/muslims; those riots are the result of a racist policy and a racist police in France. There are two ways of preventing things like this from happening again:
a) Deport all foreigners. Welcome racism.

Change the police. Integrate foreigners, give them the same rights and treatments as everyone else gets.
Michael: Whatever your source is, this isn't about muslim extremists - this is about european racism. The rest of Europe isn't much better when it comes to granting foreigners any rights at all, the french systematic racism is simply the most obvious.
There's no reason why someone outraged about having to get a permission by german bureaucracy to see a doctor should be called a muslim extremist (yes, about 20,000 people in Germany have to do get a freakin' permission to see a doctor or, coem to that, be taken into hospital)...
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