Hezbollah was in disarray on Thursday after a second wave of deadly explosions swept through its strongholds across Lebanon, putting pressure on its leader to exact revenge for the operation it blames on Israel.

The attack killed 37 people in two days, including two children, and wounded more than 2,931 others, according to Lebanese health ministry figures.

A preliminary investigation has found hundreds of pagers that exploded across Lebanon, killing at least 12 people and wounding up to 2,800, had been booby-trapped, a security source said Wednesday.

"Data indicates the devices were pre-programmed to detonate and contained explosive materials planted next to the battery," the official told AFP, requesting anonymity to discuss sensitive matters.

The U.N. human rights chief is calling for an independent investigation into mass explosions from detonating pagers in Lebanon and Syria.

Volker Türk said in a statement Wednesday that “the fear and terror unleashed is profound” and urged world leaders to step up “in defense of the rights of all people to live in peace and security.”

Sayyed Hashem Safieddine, the head of Hezbollah’s Executive Council, said Wednesday that the group will respond to Tuesday's pager explosion attack with “special punishment."

The group is in a “new confrontation with the enemy," Safieddine said.

Israel’s defense minister has declared the start of a “new phase” of the war as Israel turns its focus toward the northern front against Hezbollah in Lebanon.

Speaking to Israeli troops on Wednesday, Yoav Gallant made no mention of the mysterious explosions of electronic devices in Lebanon in recent days. But he praised the work of Israel’s army and security agencies, saying “the results are very impressive.”

Nine people were killed and over 300 wounded Wednesday when walkie-talkies exploded across Lebanon, the government said, a day after pagers used by Hezbollah blew up, killing 12 and wounding up to 2,800.

The Iran-backed group blamed Israel for the first wave of blasts on Tuesday, vowing revenge and stoking fears of all-out war in the region.

Israeli forces in the northern region are continuing their offensive and defensive exercises, the Israeli army said on Wednesday.

Iranian President Masoud Pezeshkian said Wednesday that Western backers of Israel should feel "shame" after paging devices belonging to Lebanon's Hezbollah exploded, in a deadly attack the Tehran-aligned group blamed on Israel.

"Western countries and the Americans... fully support the crimes, killings and indiscriminate assassinations of the Zionist regime," Pezeshkian said in a statement, referring to Israel, adding that the explosions should bring them "shame."

Israel decided to blow up the pager devices carried by Hezbollah members in Lebanon and Syria on Tuesday out of concern its secret operation might have been discovered by the group, three U.S. officials told U.S. news portal Axios.

The attack took place as tensions rise between Israel and Hezbollah, which U.S. officials are highly concerned will devolve into all out war.

Free Patriotic Movement leader Jebran Bassil described the pager explosions that rocked Lebanon as “an attack on entire Lebanon, not on a party or a sect in it.”