The New York Times spoke to three Israeli intelligence officers who said BAC Consulting, a Hungary-based manufacturer of pagers, was a shell company set up by Mossad to rig the devices at the source before shipping them to Lebanon.

A Lebanese security source said Israel's Mossad spy agency planted explosives inside at least 5,000 pagers to target Hezbollah militants.

It took years, three different shell companies, and an explosive called pentaerythritol tetranitrate, according to reports.

At around 3:30 in the afternoon on Tuesday, the pagers across Lebanon began beeping, delivering a message from Hezbollah leadership to their operatives through a chorus of chimes, melodies, and buzzes.