Israeli airstrikes inside Lebanon on targets associated with the Hezbollah militia hit deeper than any in recent years on Monday, targeting an area close to the Syrian border.

The Israeli military said that its fighter jets had struck Hezbollah air defenses in the Bekaa Valley, about 60 miles from the Israeli border. It said that the strikes were in response to a surface-to-air missile attack that downed an Israeli drone over southern Lebanon. Hezbollah claimed responsibility for that attack.

At least two Hezbollah fighters were killed in the Israeli airstrikes and at least six other people were wounded, according to Bachir Khodor, mayor of the nearby city of Baalbek. Video from the scene provided by Mr. Khodor, which could not be independently verified, showed a building reduced to rubble and people on stretchers being loaded into an ambulance.

The Bekaa Valley, a fertile plain that runs along the Syrian border, has long been a stronghold for Hezbollah, the politically powerful Lebanese militia that has engaged in near-daily clashes with Israeli forces since the Hamas-led attacks in Israel on Oct. 7. The fighting has displaced more than 150,000 people on both sides of the Lebanese-Israeli border and left hundreds dead.

The airstrikes on Monday were the first time that the Israeli military had hit the Bekaa Valley during the current conflict. Its strikes have recently been moving deeper inside Lebanon. Last week, the Israeli military said that it had struck what it called Hezbollah weapons storage facilities near the Lebanese coastal city of Sidon, around 20 miles from the border with Israel.

During a meeting with military officials on Sunday, the Israeli defense minister, Yoav Gallant, said that his country was “planning to increase the firepower against Hezbollah,” adding that it would not pause operations along the border with Lebanon even if there were a temporary halt to the fighting in Gaza.

“We will increase the fire in the north separately and will continue until the full withdrawal of Hezbollah and the return of Israeli civilians to their homes,” he said.

Hassan Fadlallah, a Hezbollah lawmaker in the Lebanese Parliament, said on Monday that the latest round of Israeli strikes would “not go without a response.”

Johnatan Reiss contributed reporting from Tel Aviv.