JALAZOUN, West Bank - At least 50 people were hurt on Sunday in a clash between Palestinian police and residents of a refugee camp protesting against a strike in a UN aid agency that has paralyzed services, police and an ambulance service said.The demonstration, in Jalazoun camp in the West Bank, was the most violent in a series of protests over the past week stemming from a more than month-old strike for higher pay by local employees of the United Nations Relief and Works Agency (UNRWA).UNRWA, which employs more than 5,000 Palestinians in 19 camps for some 730,000 West Bank refugees, has been forced to shut schools, clinics and suspend trash collection at the camps since the strike began."We have nothing to do with the strike and we want to make our voice heard," said Mohammed Najar, a Jalazoun resident. "The situation in the camps cannot be tolerated: no schools, no clinics and trash is piled everywhere."Adnan Al-Dmairi, spokesman of the Palestinian security forces in the West Bank, said authorities sympathized with refugee camp residents hit by the strike but would not tolerate disorder.A police spokesman said at least 40 policemen were hurt by rocks thrown by protesters, who also blocked roads and burned tires. Police responded by hurling stones at the crowd and firing tear gas and live ammunition into the air, injuring more than 10 people, an ambulance service said.Aid agencies are struggling to cope with a deepening refugee crises related to the civil war in Syria at the same time the Palestinian economy is faltering.Many refugees fear UNRWA is slowly disengaging from its aid activities and believe the international community owes them support since it recognized Israel amid the war that led to its founding in 1948 - during which they fled or were driven from their homes to Gaza, the West Bank and surrounding countries. The UN agency has said it is trying to end the strike but does not have funds to meet the wage demands. It also says its employees get paid at least 20 percent and in some cases 80 percent more than public-sector employees in equivalent fields.