The powerful Iran-backed militant group Hezbollah continued to strike what it called military targets in northern Israel Thursday after thousands of its members were injured and several killed in an apparent Israeli operation using exploding pagers and other communication devices. The Israel Defense Forces said it was striking Hezbollah targets in Lebanon “to degrade Hezbollah’s terrorist capabilities and infrastructure.”

“The Hezbollah terrorist organization has turned southern Lebanon into a combat zone. For decades, Hezbollah has weaponized civilian homes, dug tunnels beneath them, and used civilians as human shields,” the IDF said in a statement. “The IDF is operating to bring security to northern Israel in order to enable the return of residents to their homes, as well as to achieve of all of the war goals.”

The IDF said a few hours later that the Israeli Air Force “struck hundreds of rocket launcher barrels that were ready to be used immediately to fire toward Israeli territory. Since this afternoon, the IAF has struck approximately 100 launchers and additional terrorist infrastructure sites.”

Hezbollah had already vowed to retaliate against Israel for the exploding device attacks, and the group’s leader Hassan Nasrallah, speaking Thursday, accused Israel of crossing “red lines” with its actions, which he said amounted to a declaration of war.

Israeli officials have not publicly taken responsibility for the explosions, which killed at least 32 people and wounded some 3,000, according to Lebanese health officials. 

U.S. officials said the American government and military had no role in the device attacks, but CBS News has learned that the U.S. did get a heads-up from Israel about 20 minutes before the operations began in Lebanon on Tuesday, though there were no specific details shared about the methods to be used.

U.S. officials said Wednesday that the Biden administration did not believe a full-scale war between Israel and Hezbollah was inevitable, but it remained unclear how significant any further Hezbollah retaliation over the coming days could be.

Israeli Defense Minister Yoav Gallant said Wednesday that his country’s war with Iran’s so-called proxy groups in the region had entered a “new phase,” announcing a shift to northern Israel after 11 months of intense conflict with Hamas in the Gaza Strip.

“The center of gravity is shifting to the north through the diversion of forces and resources,” Gallant said.

The Israel Defense Forces moved its 98th Division — comprised of several commando brigades — to Israel’s north on Wednesday, a U.S. official and another source familiar told CBS News. The division had been fighting in Gaza.

“We are at the start of a new phase in the war,” Gallant said Wednesday, adding that it would require “courage, determination and perseverance.”

Shortly after Hamas sparked the ongoing war in Gaza with its Oct. 7 attack, its Hezbollah allies began firing rockets and drones at Israel from their strongholds across the border in southern Lebanon. Since then, Hezbollah and the Israeli military have exchanged fire almost daily, forcing tens of thousands of people on both sides of the border to evacuate their homes.

“We all feel suffocated by the situation. We don’t breathe,” Sarit Zehavi, an Israeli researcher focused who worked for 15 years in Israeli military intelligence and lives in northern Israel, told CBS News.

“On October 8th, basically, the war started here, with Hezbollah,” Zehavi said. “Anti-tank missiles and drones through IDF positions at the beginning, but very quickly, it deteriorated to much more than that.”

What is the history of the Israel-Lebanon border?

Israel and Lebanon are divided not by a traditional border, but by a “line of withdrawal” known as the Blue Line, which was established when Israeli forces withdrew from the Hezbollah stronghold of southern Lebanon in 2000. Prior to that, Israel had maintained a “security zone” to prevent attacks from Palestinian groups and Hezbollah on Israeli residents living in the border area.

The Blue Line is recognized by both Lebanon and Israel, and is monitored by the United Nations Interim Force in Lebanon (UNIFIL) and Lebanese troops.

When fighting broke out again between Israel and Hezbollah in 2006, a new U.N. Security Council Resolution called for a cessation of hostilities and the withdrawal of Israeli troops once again from Lebanon. It also sought to check the extent of Hezbollah’s power, emphasizing the importance of the Lebanese state exercising “its full sovereignty, so that there will be no weapons without the consent of the Government of Lebanon and no authority other than that of the Government of Lebanon.”

Iran-backed Hezbollah has been able to maintain its power inside Lebanon and build up its arsenal, however, including its stockpiles of rockets, drones and anti-tank missiles.

“The reality is that, prior to October 7th, there was always a vulnerability, but Israel always thought it had been tamed,” Sanam Vakil, director of the Middle East and North Africa Program at the global affairs think tank Chatham House, told CBS News. “What October 7th has done, I think for Israel and Israelis, is reawaken them from, you know, that mirage that they were safe and secure. So going back to October 6th without altering the balance of power on Israel’s borders and within Israel seems hard to do.”

“They are launched against everything,” Zehavi told CBS News of Hezbollah’s attacks on Israel since Oct. 7. “Sometimes it’s tanks, and sometimes it’s homes. Sometimes it’s farmers, and sometimes it’s soldiers, and people are getting killed.”

Tens of thousands of people displaced

Zehavi said around 60,000 Israelis remain displaced from their homes near the Lebanese border amid the ongoing violence since Oct. 7, making “ghost towns” of 43 communities there.

Residents “pretty much left their homes at the beginning of the war because they were afraid of Radwan Brigades, which are the elite unit of Hezbollah, and we were afraid that they will carry out an invasion, just like Hamas,” Zehavi said.

Then there are areas which are slightly further away — between two and six miles from the border — where people are still experiencing Hezbollah attacks but have largely remained in their homes.

“Most of the fire is to the evacuated communities, but I can tell you that… since June, basically about 15% of the attacks coming from Lebanon are to the areas which are not evacuated,” Zehavi said.

She said Hezbollah rockets were relatively easy for Israel’s Iron Dome defense system to shoot down, but the group’s drones are sometimes able to get past aerial defense systems and have killed people. Anti-tank missiles are the most dangerous kind of attack, Zehavi said, because there is no warning and nothing that can be done to defend against them.

“They cannot be intercepted at all. And we don’t have an answer to these. You only have a few seconds. You don’t have alerts. They’re just launched and hit and they’re very accurate because Hezbollah has advanced anti-tank missiles,” Zehavi said.

Zehavi said even if there is a cease-fire reached between Israel and Hamas that brings a cessation of the current hostilities with Hezbollah, too, the threat from the Lebanese group will remain.

“I don’t think that Hezbollah is interested in a wide invasion now, but I think that the basic goal of Hezbollah is to carry out this kind of invasion when it’s most comfortable to them,” Zehavi said.

After Oct. 7, she said Hezbollah “lost the element of surprise, because IDF is prepared here. But imagine that we will have a cease-fire… The people will come back to the communities — they will not be empty anymore, the communities next to the border.”

“If Hezbollah will attack,” she said, “the achievement will be greater, and they will be capable of killing many civilians. IDF cannot draft these reservists [currently guarding the border region] forever.”

“The problem,” said Chatham House’s Vikal, “is that Israel’s leaders aren’t taking the real steps that could alter the balance of power,” pointing to Israel’s ongoing occupation of some Palestinian land and their calls for an independent state as what “gives air and energy to the movement.”

“If [Israel] began to think more concretely about taking air out of the balloon and and addressing their domestic security crisis — not just through military means — but through an accountability governance and peace process, that would be the most disenfranchising way of protecting their security against, you know, a Hamas or Hezbollah or Iran even,” Vikal said.

Israel’s Ambassador to the United Nations, Danny Dannon, asked about a possible escalation along the Israel-Lebanon border, told CBS News in August that “we cannot continue with the situation” with so many Israelis displaced from their homes.

“So either they [Hezbollah fighters] will move from the border, or we will have to move them,” Dannon said.

“All of us feel, all of us share the feeling that we don’t have a prospect,” Zehavi said from her home in northern Israel. “We don’t know where this is heading. There is a very high level of uncertainty. We don’t know whether this is going to develop to a full scale war tomorrow… because none of these problems were solved.”

Margaret Brennan contributed to this report.

Haley Ott

Haley Ott is the CBS News Digital international reporter, based in the CBS News London bureau.