Israel had a hand in the manufacturing of pagers that exploded on Hezbollah terrorists this week, with this type of "supply chain interdiction" operation having been planned for at least 15 years, a US intelligence source told ABC News on Thursday.
The CIA has long been reluctant to employ this tactic because the risk to innocents was too high, the source said.
Planning for the attack involved shell companies, with multiple layers of Israeli intelligence officers and their assets fronting a legitimate company that produced the pagers, the source confirmed to ABC News, with at least some of those doing the work unaware of who they were actually working for.
One to two ounces of explosives and a remote trigger switch to set off the blast were planted in the pagers, according to the sources.
ABC News reached out to BAC Consulting -- the Hungary-based company contracted to produce the pagers on behalf of Gold Apollo in Taiwan -- but neither company has responded to our repeated requests.
The pagers were never in Hungary and the company was "a trading intermediary, with no manufacturing or operational site in Hungary," a spokesperson for the Hungarian government told ABC News on Wednesday.
The New York Times reported on Wednesday night that BAC was set up by Israel specifically as part of an operation to sabotage Hezbollah.
Israel has neither responded to the explosions nor taken credit for them, but a dozen current and former defense and intelligence officials insist that Israel is behind the explosions, which they deem "attacks."
These officials told the Times, on condition of anonymity, that the operation was long and complex.
Hezbollah leader Hassan Nasrallah spoke out on Thursday for the first time about the pager and communication device explosions that killed and wounded thousands of terrorists in Lebanon.
"Israel crossed all the red lines by detonating thousands of pagers. This could be called a declaration of war," Nasrallah stated. He added that "the devices exploded in unison, in the hospitals as well. As a result of the aggression, dozens were killed, including women and children, and thousands were injured. The true numbers will come with time. This is an act of terror, massacre, genocide. More than 4,000 pagers were distributed to the organization's operatives.
"We undoubtedly suffered a major security and humanitarian blow, unprecedented in the history of man and maybe in the history of the conflict. We were hit hard, but that's the situation in war. We understand that the enemy has technological supremacy. Especially since it is supported by the US and the West. When we are in conflict we bet on Jihad, on attrition. We had many victories until now."
With this, he insisted: "The heavy blow that we suffered won't knock us down. From experience, we will become stronger, smarter, and more determined. We will be ready to overcome all of the threats and attempts in the future."
Meanwhile, Iranian Revolutionary Guards Commander Hossein Salami promised Nasrallah that the "axis of resistance" would have a "crushing response" to the explosion of the communication devices this week.
“Such terrorist acts are undoubtedly the result of the Zionist regime’s despair and successive failures. This will soon be met with a crushing response from the axis of resistance and we will witness the destruction of this bloodthirsty and criminal regime," Salami said, according to Lebanese media.