The death toll from the exploding pagers that injured thousands of Hezbollah fighters in Lebanon has risen to 12, including two young children, Lebanese authorities said Wednesday — as the terrorist group warned Israel to brace for “harsh punishment” over the massacre.

Nearly 3,000 people were left wounded when the hand-held devices started exploding nearly simultaneously Tuesday afternoon in a deadly attack that Hezbollah and the Lebanese government have blamed on “Israeli aggression.”

The injured included Iran’s ambassador to Lebanon, Mojtaba Amani, who suffered serious head injuries and lost an eye, according to Iranian state-run news outlet al-Mehr.

Hezbollah, the Iran-backed militant group, quickly vowed to retaliate against Israel over the sophisticated, remote blasts, saying Wednesday it would continue its normal strikes to support Hamas in its war against the Jewish state.

“The resistance will continue today, like any other day, its operations to support Gaza, its people and its resistance which is a separate path from the harsh punishment that the criminal enemy (Israel) should await in response to Tuesday’s massacre,” a statement from the terror group said.

“This is another reckoning that will come, God willing.”

The attack unfolded when the pagers started heating up and then exploding in their owners’ hands or pockets in the southern Lebanon suburbs of Beirut and the eastern Bekaa Valley, which are all Hezbollah strongholds.

The majority of those hit were members or linked to members of Hezbollah — whether fighters or civilians. 

Dozens gathered Wednesday in the village of Nadi Sheet to mourn Fatima Abdullah, a 9-year-old girl said to be one of two kids killed in the attacks — with her mother still proudly wearing a yellow Hezbollah scarf in support of the terror group.

It wasn’t clear if Amani, the Iranian ambassador, was carrying his own pager, or if he was injured when someone’s nearby device detonated, state media said.

Lebanon Health Minister Firas Abiad told journalists during a tour of several hospitals in Beirut early Wednesday that many of the wounded had severe injuries to the eyes, while others had limbs amputated. 

Israel has so far declined to comment on the explosions.

The AR-924 pagers that detonated were all the latest models acquired by Hezbollah in recent months.

They were distributed to members after Hezbollah’s leader warned his fighters not to carry cell phones — telling them they could be used to track their movements or carry out targeted strikes.

Israel allegedly hid explosive material in the Taiwan-made Gold Apollo pagers before they were imported to Lebanon, the New York Times reported, citing US and other officials briefed on the operation.

The material was implanted next to the battery with a switch that could be triggered remotely to detonate.

The exploding pagers were then detonated by a message impersonating the leaders of the group on Tuesday afternoon, officials said.

In the aftermath, a Hezbollah official described the incident as the “biggest security breach” for the group in nearly a year of conflict with Israel.

The US has said it was not involved in the explosions and doesn’t know who was responsible.

A company based in Hungary was responsible for manufacturing the pagers, another firm whose brand was used on the devices said Wednesday.

The pagers used in the attack were manufactured by BAC Consulting KFT, based in Budapest, according to a statement released by Gold Apollo — a Taiwanese firm that authorized the use of its brand on the pagers.

“According to the cooperation agreement, we authorize BAC to use our brand trademark for product sales in designated regions, but the design and manufacturing of the products are solely the responsibility of BAC,” Gold Apollo said in a statement.

With Post wires