Israel's Prime Minister Benjamin Netanyahu on Saturday accused Hezbollah of "trying to assassinate him", with the Middle East already on edge after Israel had vowed retaliation for an Iranian missile barrage earlier this month.
Netanyahu's office said a drone was launched towards his residence in the central town of Caesarea but he and his wife were not home and there were no injuries.
"The attempt by Iran's proxy Hezbollah to assassinate me and my wife today was a grave mistake," Netanyahu said in a statement.
"Anyone who tries to harm Israel's citizens will pay a heavy price," he said in comments directed at Tehran and "its proxies", which include Lebanon's Hezbollah, with whom it has engaged in cross-border attacks since October last year, which escalated into a war and invasion since September.
The Lebanese group did not acknowledge the attack, but late on Saturday Iran's United Nations mission said "this action was taken" by Hezbollah.
Israeli military spokesman Rear Admiral Daniel Hagari said a drone "hit a building in Caesarea, while trying to hit the prime minister".
Caesarea is about 20 kilometres (12 miles) south of the Haifa city area, which Hezbollah has regularly targeted. Ofek Mor, a 20-year-old Caesarea resident, said he felt "unsafe like I've never felt before in Israel".
The drone launch came as Hezbollah vowed to intensify attacks on Israel, in response to the killing of Hamas' leader in the Gaza Strip, Yahya Sinwar in Gaza earlier this week.
On Saturday, the Lebanese group launched rocket barrages at Israel's north, where rescuers said one man was killed by shrapnel.
"Hamas is a reality in Palestine that no one can ignore, no one can destroy," Iranian Foreign Minister Abbas Araghchi told state TV on Saturday after meeting a Hamas representative in Istanbul.
While fighting a two-front war, in Lebanon and in Gaza, Israel has also vowed to respond to Iran's October 1 missile barrage with a "deadly, precise and surprising" attack, according to Israeli Defence Minister Yoav Gallant.
Iran said it had fired 200 missiles at its arch-foe in response to the killing of an Iranian general and Hezbollah chief Hassan Nasrallah.
Gaza's civil defence agency on Saturday said that a sweeping Israeli military operation had killed more than 400 people in two weeks in the territory's north.
Hours later, it reported another Israeli air strike had killed at least 73 Palestinians in a residential area in Beit Lahia.
"There are still martyrs under the rubble," Mahmud Bassal, spokesman for the civil defence agency, told AFP.
Israel has launched a major air and ground assault on October 6, tightening its siege on the war-battered area and sending tens of thousands of people fleeing.
Civil defence spokesman Bassal said "we have recovered more than 400 martyrs from the various targeted areas in the northern Gaza Strip", including Jabalia and its refugee camp, since Israel's operation began.
Contacted by AFP, the Israeli military said it was looking into the civil defence agency's reports from Gaza, including that an overnight air raid on Jabalia killed 33 people.
"More than a year has passed, and every day our blood is shed," displaced Gazan Nasser Shaqura said outside a hospital in Deir el-Balah, where victims of an Israeli air strike were taken.
"Every day, every hour, there is a massacre," he said. "This is what our lives have become".
Palestinians are living through "unspeakable horrors" in the north of the Gaza Strip, the UN's acting humanitarian chief Joyce Msuya said on X.
In a statement after a meeting in Italy, defence ministers from G7 nations expressed concern over "the risk of further escalation" in the Middle East as well as "threats" to the security of UN peacekeepers in southern Lebanon.
A UNIFIL statement said their Mais al-Jabal position in south Lebanon had run out of water a day earlier before being resupplied in the evening, as roads were blocked.
Clearing the roads had been delayed "due to active fighting and warnings from the IDF of military activities", the statement added.
In Lebanon, where Israel last month escalated air raids and deployed ground forces after nearly a year of cross-border exchanges with Hezbollah, state media and the health ministry reported more deadly strikes on Saturday.
Israel said its air force had struck "Hezbollah weapons storage facilities" and an intelligence centre in the group's south Beirut stronghold. Ground forces continued "targeted" raids in southern Lebanon.
Since late September, the war has killed at least 1,454 people in Lebanon, according to an AFP tally of Lebanese health ministry figures.