Khalil al-Hayya, a senior Hamas leader, vowed to make Israel pay a heavy price for its assassination of Hamas Politburo Chief Ismail Haniyeh at a press conference in Iran on Wednesday. Briefing the media some details of the assassination, he said that witnesses said a missile hit Haniyeh’s room and exploded, killing him and one of his bodyguard with doors, windows and walls being seriously damaged. Hamas is waiting for the result of Iran’s comprehensive investigation on the assassination, he added. Al-Hayya said that, targeting Lebanon and Iran, Israel is provoking the whole world, hoping to expand the conflict to the entire region. He vowed to make Israel pay a heavy price for the assassination.