Update(1050ET): An eyewitness tells Al Jazeera: “There’s more than 400 men here. Their pagers exploded, the ones they use for communication.” There are regional Lebanese media reports of over 1,200 Hezbollah operatives injured.

Reuters is confirming that Iranian Ambassador to Lebanon Mojtaba Amani is among the wounded in the series of pager explosions, based on a report in Iran’s Mehr news outlet. Follow up reports say he was only lightly injured. Some of the explosions happened in Syria as well, reports say. There are reports of civilian deaths in Beirut, including children. Some of the explosions happened inside homes, where the pagers were on shelves or bedstands.

An Al Jazeera correspondent writes, “We are talking about hundreds of members of the group in hospitals. We are seeing videos online of injuries to their arms, to their legs, even to their faces.” The Lebanese Health Ministry is urging for doctors and nurses to rush to south Beirut hospitals amid a shortage. Reuters is reporting that among the confirmed killed is a Hezbollah Member of Parliament’s son, who was part of the armed wing.

From an alleged Hezbollah source cited in AP and Israeli media:

The official, speaking on condition of anonymity because he is not authorized to speak to the media, says the explosions were the result of “a security operation that targeted the devices.”

“The enemy [Israel] stands behind this security incident,” the official says, without elaborating.

He adds that the new pagers that Hezbollah members were carrying have lithium batteries that apparently exploded.

Does this signal the start of a larger anti-Hezbollah campaign? It appears so. And Hezbollah is definitely expected to escalate from its side. This could be the start of a new Lebanon war, bigger in scope that than the 2006 war.

Many will ask: why pagers? A regional correspondent and past ZeroHedge contributor explains:

Military analyst Elijah Magnier has told Al Jazeera that Hezbollah relies heavily on the so-called pagers to avoid Israel intercepting its members’ communications.

He also suggested that these devices might have been pre-tampered before they were dispersed among Hezbollah members.

“This is not a new system. It has been used in the past,” he said. “So in this case there has been involvement of a third party … to allow access … to remotely activate the explosion,” he said.

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An apparent covert Mossad operation has unleashed chaos in a southern Beirut neighborhood on Tuesday, resulting in large-scale casualties among Hezbollah operatives and reportedly Lebanese civilians.

Telecommunications devices used by Hezbollah members began exploding, resulting in up to hundreds wounded in the suburb of Dahiyeh. There appears to be fatalities, according to graphic social media images.

Reuters reports, “Hundreds of members of the Lebanese armed group Hezbollah, including fighters and medics, were seriously wounded on Tuesday when the pagers they use to communicate exploded,” according to security sources. Al Jazeera has cited eyewitnesses who say there are over 400 victims at just one hospital.

The sudden and unexpected detonations gave way to widespread panic and chaotic scenes in images shared on social media and broadcast by Lebanese and Israeli outlets

How could the explosions have been triggered?

The likely source of the explosions is the lithium-ion battery which powers the pagers used by Hezbollah.

While lithium-ion batteries are commonly used in consumer electronics, they can explode violently in some cases.

Lithium-ion batteries detonate due to a phenomenon called thermal runaway, a chemical chain reaction which occurs when the battery experiences a rapid temperature change.

As this chemical reaction progresses it can lead to a sudden release of energy which can cause devices to explode with intense force and heat.

Thermal runaway is triggered when the battery is overheated, punctured or overcharged.

Pagers often use unencrypted communications channels and outdated software, making them extremely easy targets for an attack.

It is conceivable that an adversary of Hezbollah could have hijacked the pagers’ broadcast signal and implanted a virus that when activated caused the battery to overheat.