Maybe I should have said that there isn't a underlying political agenda here.
I could sign up to a statement like "these are not an organized political demonstration."
But that's hardly a reason to write off the political aspect of the events - people don't riot for shits and giggles. If this were an isolated alcohol-fuled riot celebrating a major sporting event, it might be a different story. As it is, the political dimension seems pretty obvious: you've got a big underclass that's sick of being rode roughshod over by the cops and marginalized by the political classes, and they want to let you know they aren't going to sit still for it any longer. Very similar to the LA riots in that sense. Or most riots, really.
They haven't issued a statement or made clear that they have one,
Open, widespread, violent opposition to the existing social order is about as direct and clear-cut a political statement as it is possible to make.
Your complaint seems to be, again, that they aren't organized, or limited, or confining themselves to peaceful democratic means. But none of that is a requirement of political action or agenda.
All things within a society stem from a political issue. The shape of my bananas is political! The fact that it seems to be the poorer parts of the cities must mean that the riots are influenced by politics in some way, (high unemployment, social inequality, bleak job prospects, sub-standard educational facilities, closing of youth centres in recent cutbacks).
More pointedly, the issue here seems to have been treatment of said underclass by the police.
My point is that even if these issues have in some way lead to the riots it is not what the riots are trying to overturn.
Why not? Because they aren't suitably organized or directed? That's what mass uprising against perception of an inequitable social order looks like. People give up their allegiance to said order, and do for themselves. That's about as clear, explicit and forceful of a political statement as can be made: "we find that this order doesn't work for us, and so we're not going to continue to play along and allow the rest of you to profit off of it. Instead, we're going to take whatever we want." The demand for a new order that addresses these issues seems clear-cut, there.