BEIRUT - The Israeli army said it launched a ground offensive in Lebanon and that its forces engaged in clashes Tuesday, further escalating the conflict after a week of intense air strikes that killed hundreds.
The UN peacekeeping mission in Lebanon said, however, the Israeli operation did not amount to a "ground incursion" and while Hezbollah denied any troops had crossed the border, an Israeli security official said localised raids had taken place and they were limited in scope.
There was no way to immediatly verify the claims, which came as Israel targeted south Beirut, Damascus and Gaza, despite international calls for restraint to avoid a regional conflagration.
Israeli Defence Minister Yoav Gallant warned the fight was far from over, even after a massive strike on Beirut killed Hezbollah chief Hassan Nasrallah on Friday. His death dealt a heavy blow to the Iran-backed group.
The Israeli military said its forces, backed by air strikes and artillery, carried out "limited, localised, targeted operations" in Lebanon.
The operations were designed to dismantle Hezbollah and restore security to the north, where Israel says 60,000 people have been displaced by Hezbollah's missile fire over the past year.
"Intense fighting is taking place in southern Lebanon," army spokesman Avichay Adraee said, warning Lebanese against travelling by vehicles south of the Litani River.
Hezbollah said later it targeted the Israeli military intelligence base of Glilot near Tel Aviv, as air raid sirens sounded and blasts rang out in the coastal city.
The Israeli military said projectiles were fired from Lebanon into the northern Israeli towns of Avivim and Metula, where Hezbollah said it targeted "enemy soldiers" with artillery.
- Calls for de-escalation -
Only hours ahead of the Israeli military's announcement, Hezbollah said it was "ready if Israel decides to enter by land".
A military official said the Lebanese national army, dwarfed by Hezbollah's military power, was "repositioning" troops farther from the border.
World leaders called for de-escalation after Israel announced the launch of the ground operation.
The United Nations warned Israel against a "large-scale ground invasion".
"With armed violence between Israel and Hezbollah boiling over, the consequences for civilians have already been terrible," Liz Throssell, spokeswoman for the UN rights office, told reporters in Geneva.
"We fear a large-scale ground invasion by Israel into Lebanon would only result in greater suffering."
US Defense Secretary Lloyd Austin late Monday gave Washington's backing to Israel "dismantling attack infrastructure along the border".
An Israeli security official said the raids were "limited in scope", while refusing to comment about a specific timeframe or the extent of the ground operation.
Later, when asked by AFP about Hezbollah denying any Israeli ground incursion, an Israeli military official said: "There are troops on the ground in south Lebanon".
But he added he was unaware if fighting was ongoing.
Lebanon's official National News Agency said an Israeli air strike Tuesday on Ain al-Helweh camp killed six people.
It also reported Israeli shelling of border settlements, killing 10 people from the same family, including at least two children, in Daoudieh village.
Elsewhere, Syria's official news agency SANA said the country's air defences 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 Israel, which has carried out hundreds of strikes on Syria in recent years.
- Israel orders Beirut evacuations -
Hezbollah began low intensity strikes on Israeli troops a day after its Palestinian ally Hamas staged its unprecedented attack on Israel on 7 October, which triggered Israel's devastating assault on the Gaza Strip.
Austin warned on Monday of "serious consequences for Iran" if Tehran directly attacks Israel.
Following a deadly strike on central Beirut Monday, 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 17 September.
Lebanese Prime Minister Najib Mikati and the UN humanitarian agency on Tuesday appealed for over $400 million in aid for the displaced, whom Mikati estimated could be as many as one million people.
- Gaza strikes -
In Gaza, the civil defence authority on Tuesday said Israeli bombing 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.
Hamas's 7 October attack on Israel resulted in the deaths of 1,205 people, mostly civilians, according to an AFP tally based on Israeli official figures that include hostages killed in captivity.
Israel's retaliatory military offensive has killed at least 41,638 people in Gaza, most of them civilians, according to figures provided by the Hamas-run territory's health ministry. The UN has described the figures as reliable.
By Layal Abou Rahal With Jay Deshmukh In Jerusalem