Israel intensified its airstrikes against Hezbollah targets in southern Lebanon on Tuesday, marking a significant escalation in a conflict that has already claimed hundreds of lives and displaced tens of thousands. The Iran-backed militant group responded by firing rockets into northern Israel, raising concerns about a broader regional confrontation involving Iran and the United States.

Hezbollah announced it had targeted several Israeli military sites overnight, including an explosives factory approximately 35 miles inside Israel and the Megiddo airfield near the town of Afula. Israeli officials reported that more than 50 projectiles were launched from Lebanon into northern Israel on Tuesday morning, most of which were intercepted.

The clashes have prompted warnings from global leaders about the potential for a wider war. Iran's President, Masoud Pezeshkian, expressed apprehension over a regional escalation but emphasized that Hezbollah "cannot stand alone" against Israel. "Hezbollah cannot stand alone against a country that is being defended and supported and supplied by Western countries, by European countries and the United States," Mr. Pezeshkian told CNN in an interview translated from Farsi.

The European Union's foreign policy chief, Josep Borrell, described the escalating hostilities as nearing a "full-fledged war." Speaking ahead of the United Nations General Assembly in New York, Mr. Borrell said, "If this is not a war situation, I don't know what you would call it," citing the mounting civilian casualties and the intensity of military operations.

The United States echoed these concerns, with a senior State Department official stating that Washington is discussing "concrete ideas" with allies to prevent the conflict from broadening. The official added, "I can't recall, at least in recent memory, a period in which an escalation or intensification led to a fundamental de-escalation and led to profound stabilization of the situation."

Monday marked Lebanon's deadliest day in nearly two decades, with at least 558 people killed by Israeli airstrikes, according to Lebanon's Health Minister Firass Abiad. Among the casualties were 50 children and 94 women. "We remain in the war and remain in the throes of the attacks. Our responsibilities have not ended," Mr. Abiad said as Israel continued its offensive on Tuesday.

The Israeli Defense Forces (IDF) confirmed completing a "second wave" of strikes on Hezbollah positions, some deep within Lebanese territory. "Among the targets struck were buildings in which weapons were stored, command centers, and additional terrorist infrastructure sites," the IDF stated, claiming that secondary explosions indicated large amounts of weapons stored in the buildings.

Israeli Defense Minister Yoav Gallant indicated that the campaign would persist until Israeli residents evacuated from northern regions could safely return home. "This is the most difficult week for Hezbollah since its establishment-the results speak for themselves," Mr. Gallant said. "Entire units were taken out of battle as a result of the activities conducted at the beginning of the week in which numerous terrorists were injured."

The intensification of airstrikes has exacerbated humanitarian concerns. Nasser Yassine, Lebanon's coordinator for emergency preparedness, told CNN that the number of displaced people from areas affected by Israeli strikes has reached 16,500 within the last 24 hours. Approximately 150 schools are being used as shelters across Lebanon.

Displaced families are seeking refuge wherever possible. In Beirut and the coastal city of Sidon, schools have been converted into makeshift shelters. Volunteers have set up kitchens to provide meals, and social media platforms are being used to offer empty apartments or spare rooms.

Lebanese Prime Minister Najib Mikati urged the United Nations and world powers to deter what he described as Israel's "plan that aims to destroy Lebanese villages and towns." Mr. Mikati announced he would cancel a scheduled cabinet meeting to travel to New York for further discussions with international leaders to seek an end to the violence.

The U.S. has announced plans to send a small number of additional troops to the Middle East in response to the escalating tensions. President Biden's administration has repeatedly called for the crisis at the Israel-Lebanon border to be resolved diplomatically. In a call with Mr. Gallant on Monday, U.S. Defense Secretary Lloyd Austin said the U.S. "remains postured to protect U.S. forces and personnel and determined to deter any regional actors from exploiting the situation or expanding the conflict."

France has requested an emergency U.N. Security Council meeting to address the situation, urging all parties to avoid a regional war. China's top diplomat, Wang Yi, expressed support for Lebanon and condemned "indiscriminate attacks against civilians," according to Beijing's foreign ministry.