Three Lebanese soldiers were killed and a fourth was critically injured on Saturday while dismantling a bomb placed by militants in a Palestinian refugee camp in northern Lebanon, officials said. The deadly blast occurred as the army was dismantling bombs, booby traps and land mines inside the camp, reported a senior military official, speaking on condition of anonymity because he was not authorized to speak to the media. Saturday's fatalities bring to 79 the number of soldiers killed in the battle against Fatah Islam Group's militants holed up in the Nahr el-Bared camp near the port city of Tripoli. More than 150 have been wounded since fighting erupted on May 20, the Associated Press reported. Heavy machine gun fire and bursts of artillery shells reverberated across the camp Saturday and sent up plumes of black and white smoke.