Angry clashes erupted Friday in the West Bank, after Palestinian leaders called for a "day of rage" in response to the shelling of a United Nations shelter that killed 16 people. At least four Palestinians were killed in outbreaks of violence in several parts of the West Bank, according to medical sources. The call for a massive follow-up to what were already some of the largest West Bank protests in years came as diplomats scrambled to find a cease-fire proposal that would satisfy mortal enemies Israel and Hamas and end more than two weeks of violence that has claimed more than 800 lives, most of them civilians. The developments come as Israel and Hamas agreed to a 12-hour humanitarian cease-fire beginning Saturday morning. Has Israel-Gaza coverage been fair? West Bank erupts in deadly demonstrations Prime Minister Benjamin Netanyahu told U.S. Secretary of State John Kerry that Israel agreed to a cease-fire, a U.S. official told