Iran's top leader has banned hard-line Iranian volunteers from leaving the country to carry out suicide bombings against Israel. Iran's state television on Thursday quoted Ayatollah Ali Khamenei as saying that Iran can't allow volunteers to cross its border and take military action against Israel. But he said Iran won't spare any efforts to assist Hamas in other ways. Hard-line Iranian student groups asked the government to authorize volunteers to go carry out suicide bombings in Israel in response to the IDF assault on the Gaza Strip. Iran is Hamas's main backer, though the country denies sending weapons to the Islamic terrorist movement.