Here are the unanswered questions. Some early speculation suggested that the pagers could have been targeted by a complex hack that caused them to explode. But that theory was quickly dismissed by experts.

Israel is believed to have conducted a series of clandestine attacks on adversaries linked to Iran in recent years, sometimes using highly innovative tactics.

Lebanese officials say more handheld devices exploded a day after thousands of pagers carried by Hezbollah members blew up in an attack blamed on Israel.

The Israeli military on Friday said it conducted a "targeted strike" in Beirut, Lebanon, after a night that saw dozens of airstrikes in one of Israel's most intense bombardments against the Hezbollah militant group in Lebanon.

Israel is the No. 1 suspect{beacon} Defense &National Security Defense &National Security   The Big Story Handheld radios explode in LebanonThe

Hezbollah launched a new barrage into northern Israel amidst growing fears of a larger conflict. Earlier this week, hundreds of electronic devices used by Hezbollah exploded, killing at least 37 and wounding 3,

In a much-anticipated speech, Hassan Nasrallah acknowledged Hezbollah had suffered an “unprecedented blow”, but he vowed it would continue fighting and inflict a “just punishment”. Israel has not said it was behind the blasts on Tuesday and Wednesday,

Hezbollah war grows as the two sides trade new fire, Hezbollah's leader accuses Israel of crossing "red lines."