Israeli settler attacks on Palestinians and their property in the West Bank have tripled in the past five years, a Washington-based think tank said Tuesday. Violence by Israelis living in Jewish-only settlements reached a peak in 2011, when the number of attacks grew by 39 percent from the previous year, according to the report by the Palestine Center. Most settler attacks now occur in the northern West Bank governorate of Nablus, overtaking the southern Hebron district as the most concentrated center of violence, the report said.