Rabbi Arik Ascherman's right middle finger is still bandaged from a recent confrontation in the West Bank, when a suspected extremist Jewish settler lurched at him with a knife, punching and kicking him.

Almost two weeks after the Oct 23 attack, when the liberal rabbi was helping Palestinians harvest their olive trees, no arrests have been made - part of what critics say is a culture of impunity for extremist settlers.

Palestinians say that Israel's seeming inability to prosecute settlers accused of violence is a key factor in a nearly two-month wave of violence that shows no signs of slowing down.