United Nations peacekeepers said three military observers and a translator were wounded Saturday in a blast in southern Lebanon, where Israel and Hezbollah militants trade frequent cross-border fire. The military observers, from Australia, Chile and Norway, and a Lebanese language assistant had been on foot patrol around the so-called Blue Line, the UN-demarcated border between Israel and Lebanon. The four “were injured when an explosion occurred near their location”, according to Andrea Tenenti, a spokesperson for the United Nations Interim Force in Lebanon.