Israeli Prime Minister Benjamin Netanyahu, left, walks with President Isaac Herzog, center right, at Mount Herzl Military Cemetery in Jerusalem on Sunday. Naama Grynbaum/Pool via AP

JERUSALEM — A drone attack from Lebanon injured an Israeli officer and a soldier near Israel’s northern border early Monday after an exchange of fire overnight, Israel’s military said, as Israel remains on alert for the major retaliation promised by its adversaries after senior Hamas and Hezbollah officials were killed last week.

Meanwhile, diplomatic efforts continued over the weekend in an attempt to defuse regional tensions and avert an all-out war beyond the current conflict between Israel and Hamas in Gaza, where more than 2 million Palestinians remain under Israeli siege and near-constant bombardment.

Hezbollah, the Iranian-backed militia group in Lebanon that has been exchanging barrages with Israel on a near-daily basis for months, claimed responsibility for Monday’s strike, saying it targeted an Israeli military base.

Israel and Hezbollah had exchanged fire overnight, with the Israel Defense Forces saying early Monday that “a suspicious aerial target that crossed from Lebanon” was intercepted in the air and that an explosive drone crossed into Israel from Lebanon but “fell in the area of Malkia,” in the northeast.

The IDF said it struck infrastructure in Lebanon that it said was used by Hezbollah, including to store weapons, and fired artillery toward Chebaa and Rachaya Al Foukhar in southern Lebanon.

“We are in strong readiness for defense in the air, at sea and on land, and we are preparing for any sudden threat,” Israel Defense Forces spokesman Daniel Hagari said in a Monday news briefing.

Hamas and Iran have blamed Israel for the Wednesday assassination of Ismail Haniyeh, Hamas’ top political leader, while an Israeli airstrike killed a Hezbollah senior commander and five other people in Lebanon a day earlier. Israel has declined to comment on Haniyeh’s death.

Iran Foreign Ministry spokesman Nasser Kanaani blamed Israel on Monday for the instability in the Middle East, saying that “Iran is not seeking to escalate tensions in the region.”

“If Iran uses its right to punish (Israel), it is to establish stability in the region,” Kanaani said at a news conference.

But in a sign of the rising fears, Jordanian Foreign Minister Ayman Safadi paid a rare visit to Tehran, delivering a message from Jordan’s King Abdullah II about the “dangerous escalation” taking place in the region. Jordan is a close Western ally and helped intercept Iranian weapons fired toward Israel in April.

Safadi met with newly elected Iranian President Masoud Pezeshkian on Sunday. According to state media, the Iranian president said during the talks that the assassination of Haniyeh was a “big mistake” and “will not go unanswered.”

The Organization of Islamic Cooperation, an intergovernmental body made up of 57 nations, announced that it would hold a special meeting of foreign ministers in Jeddah, Saudi Arabia, on Wednesday to discuss the war in Gaza, the killing of Haniyeh and Israel’s “aggressions against the sovereignty” of Iran.

Israeli Prime Minister Benjamin Netanyahu held a meeting of his security cabinet Sunday to discuss preparations for any counterstrike. In a statement released by his office, Netanyahu said Israel is “determined to stand” against Iran and its proxies “on every front and in every arena – near and far.”

Separately, at least 30 Palestinians were killed Sunday in strikes on two schools in Gaza City, where thousands of displaced people were sheltering, a spokesperson for Gaza’s Civil Defense said. An eyewitness to the aftermath, Osama Labad, 35, said by phone that women and children were among the dead and injured. The Israel Defense Forces said the strikes targeted Hamas militants using the schools as “command and control centers.”

Also Sunday, two people were killed in a stabbing attack by a Palestinian in a Tel Aviv suburb, according to Israeli authorities.

WHAT ELSE TO KNOW

President Biden will convene his national security team Monday to discuss Middle East developments, according to the White House. He is also set to speak with Abdullah of Jordan.

Hundreds of ultra-Orthodox and Haredi Jews clashed with police during a protest of military conscription Monday as the first round of previously exempted religious Jews were summoned for military service. In June, Israel’s high court ruled that they were eligible for conscription after a long-standing law excusing them expired, but many ultra-Orthodox leaders have called on their communities to refuse to serve in the military as they say it is a threat to their highly insular and religious way of life. The issue has threatened the political future of Netanyahu, who needs the support of the religious parties to maintain his ruling coalition.

At least 39,623 people have been killed and 91,469 injured in Gaza since the war began, according to the Gaza Health Ministry, which does not distinguish between civilians and combatants but says the majority of the dead are women and children. Israel estimates that about 1,200 people were killed in Hamas’s Oct. 7 attack, including more than 300 soldiers, and says 329 soldiers have been killed since the launch of its military operation in Gaza.

Pannet reported from Wellington, New Zealand, and Timsit reported from Paris. Washington Post writer Susannah George in Beirut contributed to this report.