BEIRUT/HAIFA, Israel  -  Hezbollah and Israel exchanged heavy fire into Sunday, as the Lebanese group sent rockets deep into northern Israeli territory after facing some of the most intense bombardment in almost a year of conflict.

Hezbollah deputy chief Naim Qassem told mourners at the funeral of one of the group’s commanders killed last week in Beirut: “We have entered a new phase, the title of which is the open-ended battle of reckoning.”

Israeli Defence Minister Yoav Gallant said operations would continue until it was safe for evacuated people on his side of the border to return - also setting the stage for a long conflict as Iran-backed Hezbollah has vowed to fight on until a ceasefire in the parallel Gaza war.

 Israel’s Chief of the General Staff Herzi Halevi said in a televised statement the military was well-prepared for the next stages of fighting, which were coming in the next few days, but did not say what this would entail.

“We will do whatever it takes to removes threats against Israel,” Halevi said in a televised statement. The conflict - which has escalated sharply in the past week - has raged since Hezbollah opened a second front against Israel, saying it was acting in support of Palestinians facing an Israeli offensive further south in Gaza.

On Tuesday and Wednesday, thousands of pagers and walkie-talkies used by Hezbollah members exploded. The attack was widely blamed on Israel, which has not confirmed or denied responsibility.

The following day, Israel launched its heaviest bombardment of Lebanon yet.

On Friday an Israeli airstrike on Beirut’s southern suburb targeted senior Hezbollah commanders in an attack that killed 45 people, according to the Lebanese health ministry. Hezbollah said 16 members of the group were among the dead, including senior leader Ibrahim Aqil and another commander, Ahmed Wahbi.

In a further intense bombardment on Saturday the Israeli military said it struck around 290 targets, including thousands of Hezbollah rocket launcher barrels.

“In recent days we have inflicted a series of blows on Hezbollah that it never imagined,” Israeli Prime Minister Benjamin Netanyahu said in a video statement. “If Hezbollah has not understood the message, I promise you, it will understand the message.”

Speaking at Aqil’s funeral on Sunday, Hezbollah’s Qassem said Israel was seeking to paralyse the group, but would not succeed.

Qassem said Israel’s escalation of the conflict would lead to further displacement of its own citizens.

Israel has closed schools, restricted gatherings in the north and ordered hospitals there to move patients and staff to protected areas - many have secured or underground facilities designed to withstand rocket fire.

Air raid sirens sounded constantly in Israel on Sunday. About 150 rockets, cruise missiles and drones were fired at Israel overnight and into Sunday, most of which were intercepted by air defences, the military said.

Several buildings were struck, including a house badly damaged near the city of Haifa. Rescue teams treated wounded but there were no reports of deaths. Residents had been instructed to stay near bomb shelters and safe rooms.

Hezbollah said it hit a barracks and another Israeli position with squadrons of attack drones and also launched rockets at military-industrial facilities in an “initial response” to the device attacks last week.

An official in the Islamic Resistance in Iraq, a grouping of Iran-backed armed factions, said they launched cruise missile and explosive drone attacks at Israel at dawn on Sunday as part of “a new phase in our support front” with Lebanon.

“Escalation in Lebanon means escalation from Iraq,” the official said.

The U.N. special coordinator in Lebanon, Jeanine Hennis-Plasscharet, said in a post on X that “with the region on the brink of an imminent catastrophe, it cannot be overstated enough: there is NO military solution that will make either side safer”.

Lebanon’s top Christian cleric, Bechara Boutros al-Rai, said in his Sunday sermon that Lebanon was “deeply saddened” by the casualties among civilians and within Hezbollah in the attacks of the past week, in a rare condolence message by a Christian leader to the group.

“We direct an appeal to the (United Nations Security Council) to put an end to this war by all available means,” Rai said.

Meanwhile, an Israeli airstrike killed seven people in a school sheltering displaced families in Gaza City on Sunday, Palestinian health officials said, with the Israeli military saying it had targeted fighters operating from the compound.

The strike hit Kafr Qasem School in Beach camp at around 11 am (0800 GMT), the officials said. Among those killed was Majed Saleh, the director of the Hamas-run Public Works and Housing ministry, they added.

Israel’s military said the strike targeted Hamas fighters there, and that it had used aerial surveillance and taken other steps to limit the risk to civilians.

The attack and other reported violence in Gaza came amid a surge of strikes further north between Israel and the Iran-backed forces of Hezbollah across the border with Lebanon - a parallel conflict that had stoked fears of wider regional unrest.

Six other Palestinians were killed in separate airstrikes in central and southern parts of Gaza, the medics said. They put the number of Palestinians killed in Israeli strikes so far on Sunday at 16.

In Rafah, near Gaza’s border with Egypt, residents said Israeli tanks advanced towards the western parts of the city, where the army has operated since May, and took positions over some hilltops overseeing the coastal road.

Israel’s demands to keep control of the southern border line between Rafah and Egypt have been a major sticking point in internationals effort to conclude a ceasefire deal between Israel and Hamas.

Hamas’s armed wing said fighters have mounted several attacks against Israeli forces in Rafah, firing anti-tank rockets and detonating bombs in houses where Israeli troops had taken positions.

On Sunday, Gaza’s health ministry warned that all services in all hospitals could halt in 10 days because of the shortages in essential spare parts, and oil needed to operate the fuel-powered generators.

Adding to the turmoil and misery, heavy rain flooded tent encampments overnight.

“Ten minutes of rain were enough to sink the tents. What if it rained all day? Tents are already worn out and can’t stand winter,” said Aya, displaced with her family in the central city of Deir Al-Balah, where around a million people are sheltering.

“We don’t want new tents. We want the war to end. We don’t want temporary solutions in hell,” the 30-year-old told media via a chat app.

More shelters and supplies to help people cope with the coming winter were needed, Juliette Touma, Director of Communications of the U.N. Palestinian refugee agency UNRWA, said.

“With rain and temperatures dropping, people are likely to fall ill especially children who are most vulnerable to colds and flu,” Touma told media.

This war in the decades-old Israeli-Palestinian conflict was triggered on Oct. 7 when Hamas attacked Israel, killing 1,200 people and taking about 250 hostages, according to Israeli tallies.

Israel’s subsequent assault on the enclave has killed more than 41,300 Palestinians, according to the local health ministry, and displaced nearly the entire 2.3 million-strong population.