A day later, a similar attack struck walkie-talkies. In total, the explosions killed at least 37 people and injured more than 3,000, many of them civilians. Israel is widely believed to be behind the blasts, although it has neither confirmed nor denied responsibility.

Bulgaria and Norway became new focal points on Thursday of a global hunt for who supplied Hezbollah with the thousands of pagers that exploded in Lebanon this week in a deadly blow to the militant group.

New explosions linked to electronic devices killed at least one person and injured at least 100, a day after pagers used by Hezbollah exploded, wounding thousands.

In Lebanon, exploding pagers and booby-trapped walkie-talkies – believed to be set off by Israel – have rattled Hezbollah and captured the world’s attention. What do they portend?

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