Two Indonesian peacekeepers were killed in southern Lebanon on Monday when an "explosion of unknown origin destroyed their vehicle", the UN agency tasked with policing the region has said. A third peacekeeper was "severely" injured in the explosion, and a fourth was hurt, the United Nations Interim Force in Lebanon (Unifil) said in a statement. It is the second fatal incident in the last 24 hours, Unifil noted. A peacekeeper - who was also Indonesian - was killed on Sunday night when a projectile, also of unknown origin, exploded in Adchit Al Qusayr in southern Lebanon. Unifil said it had launched investigations to determine what happened in both incidents. The deaths come shortly after the Israeli military announced it would step up ground and air attacks against the Lebanese armed group Hezbollah. Hezbollah, an Iranian-backed militia as well as a political party, has fired rockets into Israel in retaliation for the ongoing US-Israeli strikes on Iran.…