Beirut, Lebanon – At least nine people were killed and about 3,000 injured, including the Iranian ambassador to Lebanon, when thousands of pagers exploded – almost simultaneously – in Lebanon.

Tuesday’s attack, which reportedly targeted members of the Hezbollah group, caused chaos in civilian areas and paralyzed hospitals.

A resident of the Burj al-Barajneh refugee camp told Al Jazeera that traffic was heavy as bloodied people arrived at the nearby Al Rassoul al-Azam hospital.

Lebanese hospitals called for all available doctors to come forward as wounded people poured in need of treatment, many covered in blood and in visible pain.

According to Iranian media, the Iranian ambassador to Lebanon, Mojtaba Amani, was injured by an exploding pager.

The Iranian mission in Beirut later posted a message on X, formerly Twitter, saying that Amani’s treatment was “progressing well.” It also added that reports about his “physical condition and eyesight are false.”

Attacks were also reported in neighboring Syria.

Hezbollah promises ‘fair punishment’

Videos circulated online of men out and about – buying fruit or checking out at the supermarket – when a small explosion knocked them to the ground and bystanders ran away from the blast.

Lebanon’s Health Minister Firass Abiad said more than 200 people were in critical condition in about 150 hospitals, with most of the injuries to the face, hands and stomach.

People across the country described horrific scenes as explosions rang out in the streets and screams of pain were heard.

Among the dead was Fatima Abdallah Jaafar, a 10-year-old girl from Saraaine in Lebanon’s Bekaa Valley, who died when her father’s pager exploded.

Hezbollah blamed Israel and declared it would impose “fair punishment” on its enemies.

The Lebanese government also held Israel responsible for the attack.

Israel, however, refrained from commenting. Israeli media reported that Prime Minister Benjamin Netanyahu’s office had instructed ministers not to give interviews at this time.

Earlier on Tuesday, Israel announced it was expanding its war aims to include allowing residents of the north to return to their homes.

This expands the war aims from Gaza to the Lebanese border, while Israeli rhetoric about an extended war – including a possible ground invasion – intensifies.

Israeli Defense Minister Yoav Gallant said time was running out to avoid a military confrontation in Lebanon and that the “only way to ensure the return of Israel’s northern communities” would be military action.

Hezbollah officials have said since October last year that they consider the fighting to be over if a ceasefire is reached in Gaza.

Suspicions and conspiracy theorists

The United States has so far denied all information about the attack.

U.S. officials said they had no prior knowledge and were still gathering facts. Speaking to reporters on Tuesday, U.S. State Department spokesman Matthew Miller said the U.S. wants a “diplomatic solution” to the conflict between Israel and Hezbollah.

The scale of the attack shocked many, sparking speculation about how Hezbollah’s communications network had been penetrated and conspiracy theories arose.

In a message that quickly spread via WhatsApp, a woman claimed that the American University of Beirut Medical Center (AUBMC) was already aware of the attack.

The reason for this appears to be that AUBMC switched to a new system on August 29.

However, following the rumors, AUBMC has revealed that the paging system upgrade was already implemented in April and what happened in August was just an activation.

Deep security breach

Hezbollah recently received a shipment of pagers after Secretary-General Hassan Nasrallah urged members to stop using mobile phones to avoid being hacked or targeted by Israeli airstrikes.

Photos of the pagers show that they were AR-924s from the Taiwanese company Gold Apollo. The company soon announced that it had given a Hungarian company called BAC permission to use the Gold Apollo trademark for certain regions.

The AR-924, the statement said, “is manufactured and sold by BAC. We grant trademark authorization only.”

According to Ralph Baydoun, a data analyst at Influeanswers in Beirut, the aftermath posed a second risk to Hezbollah. He said that after the attack, “(the Israelis) would know the names and locations of all the agents who were attacked.”

“In addition, they could easily monitor traffic in and out of hospitals through their eyes and ears from the air or by hacking into surveillance cameras on roads or in hospitals or the systems within hospitals.”

Defense analyst Hamze Attar said it was Israel telling Hezbollah, “We can do more harm to you than this.”

Chris Hunter, a former British Army officer and bomb disposal expert, agreed.

“They are sending a message to every enemy of Israel in the world: ‘You could be next,’” he said.

“They’re also sending a message to say, ‘We can target anything, we can target your communications network, we can target something that’s on your body, we can even target something that you’re probably carrying in your pants, your pocket, your pocket, and that will make it so that you can never have children again.’

“Such messages are very, very powerful.”

Embedded explosives

Officials have not confirmed how the explosions occurred.

Immediately after the attack, some analysts suspected that the pagers had been hacked, causing the lithium batteries to overheat and explode.

But as more videos of the explosions emerged and more details about the casualties emerged, several analysts pointed to manipulation of the supply chain or of hardware before it ended up in Hezbollah’s hands.

Several analysts agreed that explosives could have been placed in the batteries and then activated by a coordinated message or code.

Hunter, the bomb disposal expert, said the explosion and injuries were not comparable to lithium battery explosions and that it was unlikely that so many batteries could explode at once.

“First of all, you can’t just explode a large number of lithium batteries at once by just sending some kind of pulse to a beeper,” he told Al Jazeera.

“Secondly, the explosion is not consistent. Lithium batteries go ‘bang’ and they burn, but they do not cause injuries from high explosive explosions.

“The blast wounds that I’ve seen are all consistent with about 1 to 2 ounces – 50 to 60 grams – of military-grade explosives that you might put in a pager.”

Hunter, who also testified as an expert witness at Rafik Hariri’s trial in The Hague, said that all the Hezbollah phones he analyzed in that case came from at most one or two suppliers.

“They tried to keep it secret and Israel knows that,” he said, suggesting that Israeli agents likely gained access to the pagers at the source, at the manufacturing facility, and somehow, through “coercion” or “manipulation,” got the supplier – consciously or unconsciously – to deliver the pagers.

“Then you could send one message at a time and place of your choosing and that would cause all those pagers to go off,” he said.

“It sounds like a conspiracy theory, but we know that Israel carries out very imaginative attacks.”

Other experts agreed that the devices were likely compromised with explosives.

“Everything could be manipulated,” Attar said.

“Think about an intelligence officer, if you’re planning something that complicated that goes off in one day, you’re going to work on all the elements… you’ve got to work on the pager casing itself, and the explosives (in the battery), and the microprocessor, and the safety trigger. It’s layered.”

Attar said that whatever was tampered with, it had to be done in a manner that would pass Hezbollah inspections.

Imbalance in technology and capacity

Although Hezbollah promised a response, analysts said Tuesday’s attack showed a stark difference in technological capabilities between the two sides.

“When you want to go to war with someone else who has such technological advances and the capabilities to manipulate supply chains and hack into them and things like that, then there is an imbalance,” Hadi El Khoury, a Paris-based cybersecurity expert, told Al Jazeera.

“If you don’t have your own supply chain, the device in your pocket is not hacker-proof.”

As for Iran or their allies in the “axis of resistance,” “when they use Siemens or Microsoft Windows or any technology that comes from the West, it means that somehow, somewhere, you will have a weak element in your chain,” El Khoury said.

Analysts say the level of sophistication of the attack is forcing Hezbollah to rethink its communications strategy and much more.

Hezbollah needs to “think about the supply chains for the walkie-talkies they import and the UAVs and drones,” Attar said.

“There is a supply chain in all of this and now they have to think about what in that supply chain has been compromised.”