Israel attacked Hezbollah targets in southern Lebanon and the Iran-backed militant Islamist organization fired rockets into northern Israel on Tuesday, a day after a wave of Israeli airstrikes in Lebanon killed nearly 500 people and forced tens of thousands to flee.

Hezbollah said it had targeted several Israeli military targets overnight, including an explosives factory about 60 kilometers inland from Israel and the Megiddo airfield near the city of Afula, which it had attacked three times.

According to official reports in Israel, more than 50 missiles were fired from Lebanon into the north of the country on Tuesday morning, most of which were intercepted.

The fighting has raised fears that the United States, a close ally of Israel, and Iran, which has proxies across the Middle East, could be drawn into a wider conflict. On Tuesday, Iranian President Masoud Pezeshkian expressed fears of a regional conflagration but said Hezbollah, which Iran helped found in 1983, could not stand “alone” against Israel.

“Hebzollah cannot stand alone against a country that is defended, supported and supplied by Western countries, by European countries and by the United States,” Pezeshkian said in an interview with CNN translated from Farsi into English.

EU foreign policy chief Josep Borrell described the escalating conflict between Israel and Hezbollah as almost a “full-blown war” as world leaders gathered in New York for the opening of the 79th United Nations General Assembly.

“If this is not a war situation, I don’t know what to call it,” Borrell told the UN meeting, pointing to the rising number of civilian casualties and the intensity of military strikes. He said efforts to ease tensions were continuing but Europe’s worst fears of the crisis spreading were becoming a reality.

The United States also echoed this warning. A senior US State Department official said Washington was discussing “concrete ideas” with its allies and partners to prevent the war from escalating.

Diplomatic efforts seem to have had little effect so far: Lebanon recorded more casualties on Monday than on any other day since the 15-year civil war that began in 1975.

Israeli officials have said the recent increase in air strikes on Hezbollah targets in Lebanon is intended to force the group to agree to a diplomatic solution, stop its attacks on Israel or unilaterally withdraw its troops from near the disputed border.

Many experts and politicians doubt that such strategic goals can be achieved through air power or other military operations. Others point out that Hezbollah has repeatedly stated that it will stop shelling Israel if there is a ceasefire in Gaza.

A US State Department official said: “I cannot recall a time, at least in recent memory, when escalation or aggravation has led to a fundamental de-escalation and a profound stabilization of the situation.”

After nearly a year of war against Hamas in Gaza, Israel has shifted its focus to its northern border. In the days following the October 7 Hamas attack on southern Israel that sparked the conflict, some 60,000 people were evacuated from northern Israel. Ongoing exchanges of fire across the disputed border with Lebanon are preventing them from returning.

Yoav Gallant, Israel’s defense minister, said the airstrikes would continue until residents were back in their homes. He said Monday was a “significant high point” in the nearly year-long conflict.

“This is the most difficult week for Hezbollah since its founding – the results speak for themselves,” Gallant said. “The activities earlier in the week, which resulted in numerous terrorist injuries, took entire units out of the fight.”

The Israeli military said the Israeli strikes hit long-range cruise missiles, heavy missiles, short-range missiles and explosive drones.

While Hezbollah remains defiant, there is no doubt that the waves of attacks have increased the pressure on the group, which already suffered heavy losses last week when thousands of its members’ pagers and walkie-talkies exploded.

The operation left 42 people dead and several thousand injured. The blame was widely placed on Israel, which has neither confirmed nor denied responsibility.

The United States has announced that it will send a small number of additional troops to the Middle East in light of escalating tensions.

Lebanese Prime Minister Najib Mikati called on the UN and world powers to stop Israel’s “plan to destroy Lebanese villages and towns.” He said he would cancel a planned cabinet meeting to fly to New York and “make further contacts” with politicians there to try to end the violence.

In Lebanon, displaced families slept in makeshift shelters hastily set up in schools in Beirut and the coastal city of Sidon. With hotels quickly booked up or room rates unaffordable for many families, those who could not find accommodation slept in their cars, in parks or by the sea.

In social media posts, benefactors offered empty apartments or rooms in their homes, while volunteers set up a kitchen in an empty gas station in Beirut to cook meals for the displaced.

In the eastern Zimbabwean city of Baalbek, the state news agency reported that queues had formed outside bakeries and gas stations as residents rushed to stock up on essentials in anticipation of further strikes.

In northern Israel, the Galilee Medical Center said two people arrived with minor head injuries after a rocket hit near their car. Several others were treated for minor injuries sustained while running to shelters and in traffic accidents when alarms went off.

Joe Biden’s administration has repeatedly called for a diplomatic resolution of the border crisis between Israel and Lebanon, but in a phone call with Gallant on Monday, he said the US “remains capable of protecting US forces and personnel and is committed to deterring regional actors from exploiting the situation or escalating the conflict.”

French politicians have called for an extraordinary meeting of the UN Security Council to discuss the situation and called on all sides to prevent a regional conflagration.

China’s top diplomat Wang Yi expressed his support for Lebanon and condemned what he saw as “indiscriminate attacks on civilians,” Beijing’s Foreign Ministry said on Tuesday.