Intelligence shared by Israel with the US suggests that a small number of Hamas terrorists planning the October 7 massacre and kidnapping operation near the Gaza border communicated by means of a network of hardwired phones in Gaza's tunnel system, CNN reported, quoting sources. The sources also told CNN that the plans were not shared with the vast majority of terrorists who participated in the October 7 events, and that the planning took two years. The phone lines allowed Hamas terrorists to communicate with each other while avoiding detection by intelligence officials, they added. For this reason the terrorists did not use cell phones or computers during the two-year planning period. One of the sources explained to CNN , "There wasn’t a lot of discussion and back and forth and coordination outside of the immediate area." Related articles: 'Destroy Hamas, as we destroyed the Germans and Japanese' Khamenei congratulates Islamic Jihad for 'victory in Gaza' Hostage's partner notified he will be released on Saturday 'PA continues its deception; Turkey working to rebuild Hezbollah' The sources added that the cell waited until just prior to the attack to prepare the larger group of terrorists who would carry out the massacre. One source said that the ground unit of terrorists and terror commanders trained for many months, but were not told details until the final days before the attack on Israel, explaining, "That’s how you compartment and keep something that’s tight." A source also said that the terrorists trained above ground, but their activities were not sufficiently unique to alarm Israel. CNN noted that "the US Office of the Director of National Intelligence declined to comment and the Israeli embassy in Washington did not respond to a request for comment." This is not the first time terrorists have used "low-tech" communications systems: Earlier this year, during an IDF operation in Jenin, Israeli forces discovered secure, hardwired communication lines and closed-circuit surveillance cameras.