What's the best way to protest in a country that regularly sells gasoline for less than $1.00 per gallon? You fill tires with bottles of gasoline. Cover those with gasoline. Then throw Molotov cocktails at them. The resulting fire should make it clear how upset you are.
I'm 99% sure these are anti-government protesters upset a race is going on in a country that still treats most of its population like second class citizens. There's a 0.7% chance they're just really pissed at those quick-wear Pirellis and a 0.3% chance it's a subtle dig at Red Bull driver Sebastien Vettel over his Webber pass.
(Hat tip to @IanParkesF1!)