Israeli military crossed into southern Lebanon early Tuesday, to conduct what it calls "limited ground operations," marking a major escalation in yearlong clashes with Iranian-backed Hezbollah.

A Lebanese security official said Israel had also conducted at least six strikes on south Beirut, while Syrian state media reported deadly strikes around the capital Damascus.

Despite international calls for de-escalation, Israel has vowed to keep fighting Iran-backed Hezbollah and declared a military zone in parts of its border with Lebanon.

Israeli Defense Minister Yoav Gallant warned the battle was not over, even after a massive strike on Beirut that killed Hezbollah chief Hassan Nasrallah on Friday, dealing the group a critical blow.

Israel's military said troops, backed by airstrikes and artillery, launched ground raids targeting Hezbollah "in villages close to the border."

The targets "pose an immediate threat to Israeli communities in northern Israel," the military said.

U.S. Defense Secretary Lloyd Austin late Monday gave Washington's backing to Israel "dismantling attack infrastructure along the border."

Hezbollah has said it is "ready if Israel decides to enter by land."

Deadly Damascus strikes

As Israel announced its ground raids, Syria's official news agency SANA said the country's air defence systems had intercepted three rounds of strikes in the Damascus area.

State television said anchor Safaa Ahmad was killed "in the Israeli aggression" on Damascus, while SANA reported three civilians killed and nine others wounded.

There was no immediate comment from the Israeli military, which has carried out hundreds of strikes on Syria in recent years.

As the Israeli air force pounded south Beirut, a Palestinian camp official in south Lebanon said an Israeli strike hit Ain al-Helweh camp in the city of Sidon, targeting a Palestinian resistance member.

The strike hit "the house of the son of Mounir Maqdah," the official said, requesting anonymity to discuss sensitive matters. Israel has accused Maqdah of heading the Lebanese branch of Fatah's armed wing.

Hezbollah earlier said it "targeted" Israeli troops in the border village of Shtula, with a source close to the group saying the soldiers were "right on the border."

There was no immediate comment from Hezbollah following the Israeli army's announcement of the ground raids, but the group's al-Manar television reported the Israeli statement on its Telegram channel.

U.S. news site Axios cited two Israeli officials saying the military incursion is "targeted and limited in time and scope and is not intended to occupy southern Lebanon."

Lebanon's national army, dwarfed by Hezbollah's military power, was "repositioning" troops farther from the border, a military official told AFP.

World leaders have urged de-escalation, with U.N. Secretary-General Antonio Guterres's spokesman Stephane Dujarric saying: "We do not want any sort of ground invasion."

Israel demands Beirut evac

Israel has launched a wave of deadly airstrikes aimed at Hezbollah across Lebanon, the latest of which killed 95 people on Monday, according to Lebanon's Health Ministry.

On Monday evening, the Israeli military ordered people in three districts of southern Beirut to evacuate.

"You are located near interests and facilities belonging to the ... Hezbollah group ... you must evacuate the buildings immediately," Israeli military spokesman Avichay Adraee said.

AFP correspondents in the capital heard explosions and saw a flash around ground level.

Hezbollah began low-intensity strikes on Israeli troops a day after its Palestinian ally Hamas staged an incursion of southern Israel on Oct. 7, which triggered Israel's devastating assault on the Gaza Strip.

The border clashes rapidly escalated this month.

'Everyone is afraid'

Israel's strikes on Lebanon have killed hundreds of people over the past week and forced up to a million to flee their homes, according to Lebanese officials.

Hezbollah and other groups launched rockets, drones and missiles at Israel over the same period, causing some injuries but no deaths.

Iran has said Nasrallah's killing would bring about Israel's "destruction," though the Foreign Ministry said Monday that Tehran would not deploy any fighters to confront Israel.

Austin warned on Monday of "serious consequences for Iran" if Tehran directly attacks Israel.

Lebanese Prime Minister Najib Mikati called for a cease-fire based on a recent U.S.-French proposal, urging "an end to the Israeli aggression against Lebanon."

Earlier Monday, an Israeli strike hit a building in central Beirut, with an armed Palestinian group saying it had killed three of its members.

Central Beirut resident Kahier Bannout, 42, said it was "supposed to be a safe area – not a war zone."

"Everyone is afraid."

Lebanon's Health Minister Firass Abiad said more than 1,000 people have been killed since Sept. 17.

U.N. refugee agency chief Filippo Grandi said: "Well over 200,000 people are displaced inside Lebanon," while more than 100,000 have fled to neighbouring Syria.

'Little time'

The U.S., Qatar and Egypt tried for months to broker such a deal, which Netanyahu's critics accused him of obstructing.

In Gaza, the civil defense authority said Tuesday that Israeli bombardment on homes killed 12 people in the central Nuseirat refugee camp. Seven others were killed in Israeli strikes on a school sheltering displaced people east of Gaza City.

A U.N. Satellite Centre assessment issued Monday said "two-thirds of the total structures in the Gaza Strip have sustained damage" in nearly a year of war.

Hamas's Oct. 7 incursion on Israel caused 1,205 deaths, according to Israeli official figures that include hostages killed in captivity.

Israel's genocidal war, in comparison, has killed at least 41,615 people in Gaza, most of them civilians, according to figures provided by the territory's Health Ministry. A number acknowledged by the U.N. as reliable.