Israel struck what it said were Hezbollah arms facilities in southern Beirut on Saturday after the Lebanese armed group fired rockets into northern Israel and a spokesman said a drone was launched at Prime Minister Benjamin Netanyahu's holiday home.

Netanyahu was not there at the time, and it was not immediately clear if the building was hit. But he described it as an assassination attempt by "Iran's proxy Hezbollah" and called it a "grave mistake", as Israel prepares to retaliate for an Iranian missile barrage earlier this month.

The strikes came as medics and Hamas media in Gaza, where Israel has been fighting to root out the Palestinian militant group for more than a year, said Israeli bombardments had killed more than 100 people across the coastal enclave and a siege around three hospitals had tightened.

Promises by Israel and its enemies Hamas and Hezbollah to keep fighting have chilled hopes that the death of Hamas leader Yahya Sinwar on Wednesday might lead to truces in Gaza and Lebanon and prevent further escalation in the Middle East.

Officials, diplomats and other sources say that with U.S. elections approaching, Israel is seeking to use intensified military operations to try to shield its borders and ensure its rivals cannot regroup.

On Saturday, Israeli planes dropped leaflets over southern Gaza with a picture of Sinwar and the message: "Hamas will no longer rule Gaza".

Israeli strikes later on Saturday on a multi-floor building in the northern Gaza town of Beit Lahiya killed at least 73 people and wounded dozens, medics and Hamas media said.

The Israeli military is checking reports of casualties from an airstrike in northern Gaza, an Israeli official said, adding that a preliminary examination suggested the numbers had been exaggerated and did not match information it had received.

In Beirut's southern suburbs, Israel carried out heavy strikes on several locations, leaving thick plumes of smoke hanging over the city into the evening.

The strikes targeted "a number of Hezbollah weapons storage facilities and a Hezbollah intelligence headquarters command center", Israel's military said.

Israel had issued evacuation orders for four separate neighborhoods within the suburbs, urging residents to get 500 meters (yards) away, but carried out strikes in other areas as well, witnesses said.

Tens of thousands of people have fled the southern suburbs - once a densely populated zone that also housed Hezbollah offices and underground installations - since Israel began regular strikes there about three weeks ago.

An Israeli air attack on Sept. 27 killed Hezbollah's secretary general Hassan Nasrallah, and strikes nearby have killed other top figures from the Iran-backed group.

The United States would like to see Israel scale back some of its strikes in and around Beirut, U.S. Defense Secretary Lloyd Austin said.

Earlier on Saturday, an Israeli strike killed two people as they were travelling on Lebanon's main highway near the Christian-majority town of Jounieh. Israel's military said it was looking into the incident.

Another strike killed at least four people in Lebanon's Bekaa valley, health authorities said. One of them was the mayor of a nearby town, the second mayor to be killed this week.

In a series of Hezbollah rocket salvos in Israel, one person was killed and at least nine injured, the Israeli ambulance service said.

There was no immediate comment from Hezbollah on any drone attack targeting Netanyahu's house in the northern Israeli town of Caesarea, which the prime minister said was aimed at killing him and his wife.

The conflict over the past year has caused direct Iranian-Israeli confrontations, including missile attacks on Israel in April and on Oct. 1.

Netanyahu has vowed to respond to the October ballistic missile attack.

"I say to Iran and its proxies in its axis of evil: Anyone who tries to harm Israel's citizens will pay a heavy price," he said in a statement following the Caesarea attack.

Iran's mission to the United Nations said in a statement: "We have already responded to the Israeli regime, and the action in question has been carried out by Hezbollah in Lebanon."

Hezbollah has been trading fire with Israel since the war between Israel and Iran-backed Hamas began in Gaza last October. On Saturday alone, Hezbollah launched around 200 "projectiles," the Israeli military said.

Nearly three weeks ago, Israel launched a ground assault inside Lebanon in an attempt to stabilise the border region for its citizens who had fled the fighting.

Israel's military said on Saturday said it had destroyed tunnel shafts and underground infrastructure in southern Lebanon. It also said it had killed Hezbollah's deputy commander of the Bint Jbeil area on Friday.

The Israeli military has opened an investigation into the death of a Hezbollah detainee in Lebanon, Israeli media said.

Since October 2023, more than 2,400 people have been killed in Lebanon, most of them in the last month, according to Lebanon's health ministry, while 59 people have been killed in northern Israel and the occupied Golan Heights, according to Israeli authorities.

Hamas-led militants killed some 1,200 people and took 250 hostages in the attack that triggered the war, according to Israeli tallies. Israel's military response has left more than 42,500 people dead, Palestinian officials say.

The Israeli offensive has made most of Gaza's 2.3 million people homeless, caused widespread hunger and destroyed hospitals and schools.

COGAT, the Israeli military agency that oversees administration in the Palestinian Territories, has stepped up deliveries of aid into Gaza amid international pressure. Israel and the United Arab Emirates made an air drop of aid into southern Gaza on Saturday.

Western leaders, including U.S. President Joe Biden, have said Sinwar's death offered a chance for a deal for a truce in Gaza and the release of the remaining hostages.

Negotiations for such a deal have been stalled for weeks. U.S. Secretary of State Antony Blinken, who has led diplomatic efforts, is expected to travel to Israel on Tuesday as part of a regional tour, Axios reported on the social media platform X.