Israel planted explosives in Hezbollah's Taiwan-made pagers, Reuters reports

Israel's Mossad spy agency planted a small amount of explosives inside 5,000 Taiwan-made pagers ordered by Lebanese group Hezbollah months before Tuesday's detonations, a senior Lebanese security source and another source told Reuters.

The operation was an unprecedented Hezbollah security breach that saw thousands of pagers detonate across Lebanon, killing nine people and wounding nearly 3,000 others, including the group's fighters and Iran's envoy to Beirut.

Iran-backed Hezbollah has vowed to retaliate against Israel, whose military declined to comment on the blasts.

The plot appears to have been many months in the making, several sources told Reuters.

The senior Lebanese security source said the group had ordered 5,000 beepers made by Taiwan-based Gold Apollo, which several sources say were brought into the country earlier this year.

The senior Lebanese security source identified a photograph of the model of the pager, an AP924, which like other pagers wirelessly receive and display text messages but cannot make telephone calls.

Hezbollah fighters have been using pagers as a low-tech means of communication in an attempt to evade Israeli location-tracking, two sources familiar with the group's operations told Reuters this year.

But the senior Lebanese source said the devices had been modified by Israel's spy service "at the production level."

"The Mossad injected a board inside of the device that has explosive material that receives a code. It's very hard to detect it through any means. Even with any device or scanner," the source said.

The source said 3,000 of the pagers exploded when a coded message was sent to them, simultaneously activating the explosives.

Another security source told Reuters that up to three grams