Iran has set up sophisticated listening stations in Syria in recent months to intercept Israeli military communications, Israeli security officials said Tuesday. The officials offered no details on how many stations had been set up. They spoke on condition of anonymity because they were not authorized to disclose information about defense operations. Military officials said the listening stations received information through powerful antennas able to pick up communications from a distance of hundreds of kilometers. The antennas are receivers and do not transmit signals, so they cannot be blocked. The distance between Jerusalem and Syria's capital, Damascus, is 220 kilometers. Israel is taking new precautions because of the listening stations, the officials said. Top brass won't be allowed to bring their mobile phones into rooms where classified information is being discussed, the officials said. And generals will be assigned special areas on bases to conduct personal conversations. That way, listening stations won't be able to hear sensitive conversations that might be going on in the background while generals talk on their cellular phones, they explained. Rules governing landline conversations won't be changed because those communications are less exposed to interception. Israeli military officials say Iran helped Lebanese Hizbullah guerrillas pick up Israeli radio communications during the 2006 war between Israel and Hizbullah in Lebanon. Several months ago, all radio communications were ordered to be encrypted, security officials said. On Tuesday, Israeli intelligence officers told a parliamentary committee that Hizbullah was replenishing its arsenal with medium- and long-range missiles, and improving its systems. On a tour of the northern border Tuesday, Israeli Defense Minister Ehud Barak remarked that Hizbullah was "growing more powerful," but warned that "Israel is the strongest country in the region, and I would not recommend that anyone on the other side of the border test us."