Israeli strikes and shelling targeted overnight into Wednesday several regions in south and east Lebanon, as Israel vowed "big surprises" and escalation.

In the south, strikes targeted Deir al-Zahrani, a hezbollah-affiliated health center in Kherbet Selem, Nabatieh, Tyre, Arab Salim, Kfartebnit, Shawkin-Zebdine, Harouf, Kafra, Burj al-Shamali, Bayt Yahoun, Burj Qalaway, Mayfadoun, Dweir, Shaqra, al-Jmayjmeh, al-Sultanieh, Shebaa, al-Litani, al-Kherdali, al-Abbasiyyah, Deir Qanoun, and Srifa, killing at least 6 and wounding at least 16.

President Joseph Aoun called Wednesday for unity and solidarity and the rejection of division and sectarian provocation, hours after Israel flattened an apartment building in central Beirut and killed ten people in other neighborhoods of the city.

Israel's military claimed the building in Bashoura was being used by Hezbollah to store "millions of dollars intended to finance its activities," without providing evidence. An apartment in the building was hit last week, and the building had also been targeted in the 2024 war.

An Israeli strike on Wednesday hit a car in the center of Sidon, southern Lebanon's largest city, killing two people, including a civil defense rescuer, and wounding another.

An AFP correspondent at the scene said the strike hit near the city's civil defense headquarters and the seaside road, where many displaced people are sleeping in their cars.

Lebanon said Israel struck central Beirut early Wednesday without warning, killing at least twelve people, as the Israeli military announced it was targeting the country's south.

Lebanon's official National News Agency (NNA) said two strikes in the early hours of Wednesday hit an apartment in the central Zoqaq al-Blat neighborhood, a densely populated area close to the government's headquarters and several embassies.

Israel said late Tuesday it had struck sites "throughout Lebanon," targeting what it called Hezbollah rocket launching infrastructure after a series of air raid sirens in northern Israel.

Hezbollah chief Sheikh Naim Qassem said Tuesday that Hezbollah is in a position of "legitimate defense" in the battle against Israel, "defending the land, rejecting surrender, and protecting the nation's existence and independence."

"The high level of preparation for the battle was characterized by the ambiguity surrounding our capabilities, their limits, and their deployment, the lack of need for fixed positions, and the flexibility for resistance fighters to move from anywhere in Lebanon to the front lines to engage the enemy," Qassem said in a letter to Hezbollah's fighters.

President Joseph Aoun made two phone calls Tuesday to Minister of National Defense Michel Menassa and Army Commander General Rodolphe Haykal, offering his condolences for the death of three soldiers in the South as a result of an Israeli airstrike on the Zibdine-Nabatieh road.

Former Israeli minister Ron Dermer has confirmed for the first time that he has returned to work for Prime Minister Benjamin Netanyahu and that he has been appointed to lead negotiations with the Lebanese government.

"He asked me to get involved," said the former minister who retired from public life last November.

Threats from Israeli officials to unleash Gaza-level destruction on Lebanon are "wholly unacceptable", the U.N. said Tuesday, and warned that "deliberately attacking civilians or civilian objects amounts to a war crime".

Israel has stepped up strikes and deployed ground troops to its northern neighbor since March 2, when Lebanon was dragged into the Middle East war after Tehran ally Hezbollah attacked Israel with rockets in retaliation for the killing of Iranian supreme leader Ali Khamenei.

Youssef Assaf was in a Lebanese Red Cross ambulance when it was targeted by an Israeli strike near Tyre, in southern Lebanon. The 35-year-old paramedic died of his wounds two days later.

"I was called around 10:30 pm and told that he was wounded and in the hospital," his wife, Jeanne d'Arc Boutros, told AFP from northern Lebanon, where she had fled to a relative's home.