Hezbollah vows revenge on Israel for deadly Lebanon pager explosions

Hezbollah has vowed revenge for an unprecedented and deadly attack in Lebanon, with Israel accused of carrying out the operation by planting explosives inside thousands of pagers imported by the group months earlier.

Thousands of pagers detonated across Lebanon and in Syria, killing 12 people and wounding almost 3,000 others, including the group’s fighters and Iran’s envoy to Beirut, Mojtaba Amani. Lebanon’s health minister, Firass Abiad, said a young girl was among the dead, and that more than 200 people had critical injuries.

A senior Lebanese security source and a second source told Reuters that Israel’s spy agency, the Mossad, which has a long history of pulling off complex attacks on foreign soil, planted explosives inside the pagers. The claim was mirrored by American officials cited in US media.

Related: Exploding pager attack in Lebanon is another blow for US peace hopes

Amid growing anger in the region about the attack, the US secretary of state, Antony Blinken, said the US had not been forewarned and that it was imperative all sides avoid escalation.

Jordan’s foreign minister said Israel was pushing the Middle East to the brink of regional conflict by maintaining a dangerous escalation on several fronts. In remarks after an Islamic and Arab ministerial contact group meeting in Amman to lobby for a Gaza ceasefire, Ayman Safadi said peace would not prevail without a two-state solution.

Hezbollah’s leader, Hassan Nasrallah, is expected to give a speech on Thursday when the group’s response to the attacks is likely to be made clear.

According to unverified reports, the decision to detonate the pagers – which had reportedly been planned for the opening of a major Israeli offensive against Hezbollah, was brought forward after suspicions emerged about the devices.

Hezbollah said it was carrying out a “security and scientific investigation” into the causes of the blasts and that Israel would receive “its fair punishment”. The Lebanese information minister, Ziad Makary, condemned the attack as an “Israeli aggression”.

Quickly emerging details on the source of the pagers Hezbollah bought has traced a trail from Taiwan to Hungary.

The attack has further raised the prospect of another full-scale war in the Middle East between the Iran-backed group and its arch-foe. It emerged on Wednesday that the Israeli army had moved its 98th division, until recently deployed in the Gaza Strip, to northern Israel after a cabinet decision to shift most of the military’s capabilities to the region.

The Israeli military has not commented directly on the blasts but said senior commanders had held a situational assessment “focusing on readiness in both offence and defence in all arenas”.

The Taiwanese manufacturer linked to the pagers that exploded said the devices were made by a company in Europe.

Images of the pagers emerged in the aftermath with stickers on the back that appeared consistent with pagers made by the Taiwanese company Gold Apollo, according to Reuters analysis.

On Wednesday, the company’s founder, Hsu Ching-kuang, denied it had made the pagers, saying they were manufactured by a company in Europe that had the right to use its brand. “The product was not ours. It was only that it had our brand on it,” he said. “We are a responsible company. This is very embarrassing.”

The blasts appeared to exploit the low-tech pagers that Hezbollah has adopted to prevent the targeted assassinations of its members, who could be tracked by mobile phone signals.

A Hezbollah source said they believed the attack was in response to an alleged assassination attempt by the Shia militia of the former Israeli defence minister Moshe Ya’alon last year in a failed bomb attack.

Hospitals across Lebanon were overwhelmed with patients, and a field hospital was set up in the southern city of Tyre to accommodate wounded people. The sound of ambulance sirens was constant in Lebanon’s capital city more than three hours after the attack.

US officials are trying to de-escalate tensions between the two sides and are concerned that the Israeli prime minister, Benjamin Netanyahu, could order a ground invasion of Lebanon. The pager attack came hours after Israel announced it was broadening its aims in the war to include its fight against Hezbollah along the border with Lebanon.

Related: Hezbollah pagers: what do we know about how the attack happened?

Hezbollah confirmed in an earlier statement that the deaths included at least two of its fighters and a young girl. Later media reports said the son of the Hezbollah MP Ali Ammar also died in the explosions.

The pagers exploded in southern Lebanon, the southern suburbs of Beirut known as Dahiyeh and the eastern Bekaa Valley, all Hezbollah strongholds.

One Hezbollah official, speaking on condition of anonymity, said the detonation was the group’s “biggest security breach” since the Gaza conflict erupted on 7 October, when Hamas launched attacks in southern Israel, killing 1,200 people and taking about 250 hostage.

Jonathan Panikoff, the US government’s former deputy national intelligence officer on the Middle East, said: “This would easily be the biggest counterintelligence failure that Hezbollah has had in decades.”

The apparent sabotage attack follows months of targeted assassinations by Israel against senior Hezbollah leaders and has ratcheted up tensions between Israel and Hezbollah. An uneasy calm had prevailed in the past three weeks when both parties had appeared to step back from the brink of a regional war after a limited Hezbollah response in late August to Israel’s assassination of its top military commander, Fuad Shukr, in Beirut.

The attack also threatens to derail US efforts to prevent Iran, which backs Hezbollah, from retaliating against Israel for the July bombing in Tehran that killed the Hamas political leader, Ismail Haniyeh.

The US state department spokesperson, Matthew Miller, said it was “too early to say” how the attack would affect Gaza ceasefire talks. He told a briefing the US was not involved and did not know who was responsible.

Hamas described the attack as an “escalation” that would lead to Israel’s defeat.

• Reuters contributed to this report