Media reports new details in investigation into Hezbollah pager explosions.

A Lebanese source said radio batteries used by Hezbollah militants were filled with PETN, a hard-to-detect substance. This week's attacks, linked to the Mossad, have left thousands injured.

Experts believe that Israeli spies planted explosives in the batteries of the communication devices before they were delivered in the spring. The PETN was placed in a way that made it difficult to detect. The chemical has a high detonation rate, making it destructive.

PETN, like nitroglycerin, is used in a variety of explosive devices. Its stability and reliability make it an ideal choice for sabotage operations. The effects of the Halcyon radio explosions were devastating for Hezbollah.