A bomb exploded this morning at the Sdeh Kalev farm near Hevron, wounding three 15-year-old boys, one of them seriously. The wounded were part of a group of 50 high school and junior high school students from Kiryat Arba who went for a working-visit to the field this morning. The bomb was placed about five meters from a bus that was to take the boys back to their schools, and exploded as the last of them was getting on. The three were rushed by helicopter to Hadassah Hospital in Jerusalem. Two boys were initially listed in moderate condition. It is suspected that the terrorists are from the nearby village of Bani Naim.