BEIRUT — Walkie-talkies and solar equipment exploded in Beirut and other parts of Lebanon on Wednesday in an apparent second wave of attacks targeting devices a day after pagers used by Hezbollah blew up, state media and officials for the militant group said. At least 20 people were killed and more than 450 wounded in the second wave, the Health Ministry said.

The attacks — widely believed to be carried out by Israel to target Hezbollah but also killing civilians — have hiked fears that the two sides’ simmering conflict could escalate into all-out war.

Speaking to Israeli troops Wednesday, Israeli Defense Minister Yoav Gallant said, “We are at the start of a new phase in the war — it requires courage, determination and perseverance.” He made no mention of the exploding devices but praised the work of Israel’s army and security agencies, saying “the results are very impressive.”

In Wednesday’s attacks, Associated Press journalists heard several blasts at a funeral in Beirut for three Hezbollah members and a child killed by exploding pagers the day before. An AP photographer in the southern coastal city of Sidon saw a car and a mobile phone shop damaged after devices exploded inside of them. A girl was hurt in the south when a home solar energy system blew up, the state news agency reported.

The new blasts hit a country still roiling with confusion and anger after Tuesday’s pager bombings, which killed at least 12 people, including two children, and wounded some 2,800 others.

The second wave also deepens concern over the potentially indiscriminate casualties caused in the attacks, in which hundreds of blasts went off wherever the holder of the pager happened to be — in homes, cars, at grocery stores and in cafes, often with family or bystanders nearby.

While the pagers were used by Hezbollah members, there was no guarantee who was holding the device at the time it was detonated. Also, many of the casualties were not Hezbollah fighters, but members of the group’s extensive civilian operations mainly serving Lebanon’s Shiite community.

At least two health workers were among those killed Tuesday. Doctors, nurses, paramedics, charity workers, teachers and office administrators work for Hezbollah-linked organizations, and an unknown number had pagers.

Mary Ellen O’Connell, a professor of law and international peace studies at the University of Notre Dame in Indiana, said booby-traps are banned under international law.

“Weaponizing an object used by civilians is strictly prohibited,” she said.

The U.N. human rights chief, Volker Türk, called for an independent investigation into the mass explosions, saying, “The fear and terror unleashed is profound.”

Iran-backed Hezbollah — Lebanon’s strongest armed force — has exchanged fire with Israel’s military almost daily since Oct. 8, the day after a deadly Hamas-led assault in southern Israel triggered the war in Gaza. Since then, hundreds have been killed in strikes in Lebanon and dozens in Israel, while tens of thousands on each side of the border have been displaced. Hezbollah said its strikes are in support of its ally, Hamas.

Hezbollah announced three strikes on parts of northern Israel on Wednesday, at least one of which took place after the latest round of blasts in Lebanon.

Israeli leaders have issued warnings in recent weeks that they might increase operations against Hezbollah in Lebanon, saying they must stop the exchange of fire to allow people to return to homes near the border.

In his comments, Gallant said that after months of fighting Hamas in Gaza, “the center of gravity is shifting to the north by diverting resources and forces.”

Meanwhile, the U.N. General Assembly strongly supported a nonbinding Palestinian resolution Wednesday demanding that Israel end its “unlawful presence” in Gaza and the occupied West Bank within a year. The vote in the 193-member world body was 124-14, with 43 abstentions. Among those in opposition was the United States, Israel’s closest ally.

The pager bombings appeared to be a complex operation months in the making, with many experts believing Israel infiltrated the supply chain and rigged hundreds of pagers with explosives before they were imported to Lebanon. But little evidence has emerged so far.

Gold Apollo, a Taiwanese firm, said it authorized a Hungary-based company, BAC Consulting KFT, to use its name on devices delivered to Hezbollah. But a Hungarian government spokesman said Wednesday the pagers delivered to Hezbollah were never in Hungary and that BAC Consultants merely acted as an intermediary.

Hungarian national security services were cooperating with international partners, the Hungarian spokesman, Zoltán Kovács, posted Wednesday on X.

Wednesday’s new bombings came as Lebanese were mourning the dead from the day before.

Two explosions went off at the edges of the funeral of two fighters, a young boy and a paramedic in southern Beirut. As ambulances screeched to the scene, the ceremony continued, with a senior Hezbollah official, Hashem Safieddine, telling mourners that Israel’s “aggression will face its special punishment.”

Israeli drones buzzed overhead — as they often do over Beirut and many parts of Lebanon — as thousands of mourners marched in a procession with the four coffins to a cemetery.