The blasts began in Lebanon’s capital Beirut and several other areas of the country at about 15:45 local time (13:45 BST) on Tuesday.
Witnesses reported seeing smoke coming from people’s pockets, before seeing small explosions that sounded like fireworks and gunshots.
In one clip, CCTV footage appeared to show an explosion in a man’s trouser pocket as he stood at a shop till.
Citing US officials, the New York Times said that the pagers received messages that appeared to be coming from Hezbollah’s leadership before detonating. The messages instead appeared to trigger the devices, the outlet reported.
Explosions continued for around an hour after the initial blasts, the Reuters news agency reported.
Soon after, scores of people began arriving at hospitals across Lebanon, with witnesses reporting scenes of mass confusion.
Analysts said the most likely explanation was a supply chain attack that saw the pagers tampered with during manufacture or transit.
Reuters quoted a Lebanese security source as saying that a small quantity of explosives had been placed inside the devices months ago.
Speaking to the BBC, one ex-British Army munitions expert, who asked not to be named, speculated that the devices could have then been triggered by a remote signal.
