The Israel Defense Forces (IDF) announced early Sunday morning local time that it had launched a preemptive strike on Hezbollah positions in southern Lebanon to thwart a major imminent attack by the Iran-backed terror group.

Residents of northern Israel were advised to enter bomb shelters and “safe rooms” in their homes in anticipation of a response by Hezbollah. Israel’s missile defense system, notably the Iron Dome, was said to be intercepting rockets.

Israel’s Army Radio reported that residents were being advised to take shelter even in cities relatively far from the northern border, such as the port city of Haifa, which is in the north of the country but typically safe from rockets.

The Home Front Command prohibited public gatherings of over 130 people, from the Tel Aviv region northwards.

In a statement in Hebrew, IDF spokesman Rear Admiral Daniel Hagari said that the military had detected that Hezbollah was about to fire a large barrage of rockets and missiles into Israel. Therefore, he said, the Israel Air Force (IAF) had taken preemptive action. A response was expected from Hezbollah, and therefore he said that residents of the north should enter safe rooms for at least ten minutes. He stressed that Israel’s defenses were “not hermetic.”

Israel’s Army Radio reported that Hezbollah acknowledged that it had been about to attack, but claimed that it had, in fact, done so, prior to the Israeli airstrikes.

A more comprehensive briefing was expected.

Update: Hagari said in a public statement that the IDF would attackHezbollah “throughout Lebanon,” not just in the south as necessary. He repeated the restrictions on public gathering, and added that the Home Front Command had said people should not go to work in the northern region if they were far from a bomb shelter. “The defense is not hermetic, and therefore you should continue to listen to instructions from the Home Front Command,” he said.

Hagari concluded by saying that the IDF would do whatever was necessary to defend the citizens of Israel.

He added that Ben-Gurion airport had been closed but would reopen at 7 a.m. local time. He said that it would close again if necessary.

Asked whether the U.S. had provided intelligence that led to the preemptive strike, Hagari did not answer directly but said that Israel was cooperating with the U.S., and noted the arrival in the region Saturday of U.S. Joint Chiefs of Staff Chairman U.S. Air Force General Charles Q. Brown.

Prime Minister Benjamin Netanyahu announced that he would convene his security cabinet at the “Kirya,” the main IDF headquarters in Tel Aviv, at 7:00 a.m. Defense minister Yoav Gallant said that he had spoken with U.S. Secretary of Defense Lloyd Austin and agreed on the need to avoid a broader regional escalation (presumably, involving Iran.)

This story is developing.

Joel B. Pollak is Senior Editor-at-Large at Breitbart News and the host of Breitbart News Sunday on Sirius XM Patriot on Sunday evenings from 7 p.m. to 10 p.m. ET (4 p.m. to 7 p.m. PT). He is the author of “”The Agenda: What Trump Should Do in His First 100 Days,” available for pre-order on Amazon. He is also the author of “The Trumpian Virtues: The Lessons and Legacy of Donald Trump’s Presidency,” now available on Audible. He is a winner of the 2018 Robert Novak Journalism Alumni Fellowship. Follow him on Twitter at @joelpollak.