For millions of Lebanese, this week's mass explosion of pagers and walkie-talkies, with its bloody aftermath, is painfully similar to the horrific explosion four years ago of haphazardly stored ammonium nitrates that tore through Beirut's port,

The source of Wednesday’s explosions was not immediately clear, but the blasts came a day after thousands of pagers used by Hezbollah blew up across Lebanon.

Explosions went off in Beirut and multiple parts of Lebanon in an apparent second wave of detonations of electronic devices, officials said.