Thousands of people have reportedly been injured by exploding pagers across Lebanon and Syria. Lebanon’s health minister, Firass Abiad, said nine people, including a child, have been killed, and around 2,800 others have been injured, as reported by Lebanese state media agency NNA.

Israel carried out its operation against Hezbollah on Tuesday by hiding explosive material within a new batch of Taiwanese-made pagers imported into Lebanon, according to American and other officials briefed on the operation.

Reuters reports, based on information from a “senior Lebanese security source and another source,” that this spring, Hezbollah imported 5,000 pagers that were supposedly from Gold Apollo, a Taiwanese-based manufacturer. The source claims they were modified before shipment by Israel’s Mossad spy agency, adding a board with up to three grams of explosive material.

However, in Taiwan on Wednesday, Gold Apollo CEO Hsu Ching-Kuang told reporters that his company did not make the pagers that exploded and that they were built by a company in Europe that had licensed its brand. “The product was not ours. It was only that it had our brand on it,” said Hsu, as reported by Reuters. According to CNN, the distributor started by importing Hsu’s company’s products about three years ago and later asked to manufacture its own devices using the Gold Apollo brand.

CNN also reports that “Israel was behind the attack, which was a joint operation between Israel’s intelligence service, the Mossad, and the Israeli military.”

The papers were apparently intended as a low-tech communication device to avoid location-tracking or spyware. In a speech earlier this year, Hezbollah secretary general Hassan Nasrallah reportedly told members, “This cell phone is the collaborator and the killer.”

Reuters sources said 3,000 of the pagers exploded after 3:30PM local time once they received a coded message. According to the New York Times, the message “appeared as though it was coming from Hezbollah’s leadership.”

The explosions occurred as Hezbollah has been engaged in warfare with Israel for months, coinciding with the Israel-Hamas war in Gaza and a day after Israeli Defence Minister Yoav Gallant said time was “running out” for a diplomatic solution with the group. CNN reports the Israel Defense Forces has said it won’t comment on the detonations.

Videos of the explosions and their aftermath have already spread widely across news networks and social media (warning: the video below shows people being injured by the attacks). One appears to show a man looking down at his pager while checking out at a store before it explodes, and he’s pushed backward. Another surveillance video from a market posted by The New York Times shows a man injured after a device exploded in his bag.

Update, September 17th: Added additional details from media reports about the origins of the explosive devices.