BEIRUT (AP) — Anti-government protesters are burning tires to block roads, creating dense palls of smoke that are rising around Beirut and other parts of Lebanon. It’s an expression of anger but also helplessness. The tactic has become the hallmark of a new flare-up of demonstrations against an intransigent political class that appears to do little as Lebanon slides toward political and economic abyss. Burning tires is a cheap and easy way to block roads and was a common practice during Lebanon’s 15-year civil war. It was also used in Iraq and in Palestinian protests against Israel.