A car bomb killed a Hamas leader in Syria last week, and Syrian officials say Israel was behind it. Izz El-Dine Khalil was the director of Hamas militant activities outside the Palestinian territories. Witnesses said he got into his car and answered a cell phone call just before the explosion. Israeli intelligence operatives have a history of detonating bombs remotely by phone, and Israel has often accused Syria of harboring Palestinian terrorists. While Israeli officials refused to either confirm or deny complicity in the assassination, they hinted at a role. Just because Hamas leaders are operating from Damascus, this does not grant them immunity, said Raanan Gissin, a spokesman for Prime Minister Ariel Sharon. There are no geographical boundaries when it comes to fighting terror.