Questions raised about companies in several countries over alleged links to Israel's operation detonating communications devices in Lebanon

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.

On Friday, authorities in Taiwan and Bulgaria denied any involvement in supplying thousands of pagers that exploded

Taiwan's government and Bulgarian authorities Friday both denied making the exploding pagers used by Hezbollah in Lebanon.

Questions and speculation have swirled over where the devices came from and how they were supplied to Hezbollah .

Israel's Mossad spy agency planted a small amount of explosives inside 5000 Taiwan-made pagers ordered by Lebanese group Hezbollah months before Tuesday's detonations, sources told Reuters.

Israel had a hand in the actual manufacturing of the pagers that exploded on Hezbollah operatives this week, an attack that was in planning for at least 15 years.

Walkie-talkies and pagers used by Lebanon's Hezbollah group detonated in homes and businesses across the country.

By Ben Blanchard and Faith Hung TAIPEI (Reuters) -Authorities in Taiwan and Bulgaria on Friday denied involvement in the supply chain of thousands of pagers that detonated on Tuesday in Lebanon in a deadly blow to Hezbollah.

Pagers, used every day by health care professionals, became a deadly weapon Tuesday as thousands of them simultaneously exploded in Lebanon.