Israel's military said it launched an airstrike in the Beirut area on Thursday as a Lebanese source said an apartment was hit, the second such raid since an April ceasefire announcement.
The escalation comes as Lebanon and Israel prepare for talks between military delegations at the Pentagon on Friday, and for US-brokered talks early next week - the fourth round since the latest Israel-Hezbollah war erupted on 2 March.
After heavy strikes that killed at least 14 people including three children, Israel's military said it "precisely struck in Beirut", without identifying the target.
A Lebanese military source, requesting anonymity, told AFP that "an Israeli strike targeted an apartment in the Choueifat area". AFPTV footage showed smoke rising from the area on the edge of Beirut's southern suburbs, a Hezbollah stronghold.
An AFP correspondent said the first two floors of a residential building were damaged, and saw residents packing cars and leaving.
It was the second Israeli strike on south Beirut since a ceasefire between Israel and the Iran-backed Hezbollah that was supposed to have taken effect on 17 April.
Israel has carried out near-daily violations in Lebanon, with Hezbollah fighters retaliating with attacks on Israeli troops , who have now crossed the 'Yellow Line'.
Hezbollah on Thursday claimed several attacks with rockets and drones on Israeli troops in south Lebanon.
Spokesperson for the United Nations Interim Force in Lebanon (UNIFIL) peacekeepers Kandice Ardiel told AFP that last month's agreement "had a positive effect in lessening the violence, but (we) have seen an escalation in recent weeks, and an intense escalation in recent days".
The force said in a statement that "Wednesday saw around 670 projectiles fired - the highest level since 17 April". 'Cultural landmarks' On Wednesday, Israel's military declared all areas south of Lebanon's Zahrani River - around 40 kilometres (25 miles) from the border and including the cities of Tyre and Nabatieh - to be "combat zones" and told residents to evacuate.
This week, Israel vowed to ramp up operations in Lebanon and said it was expanding ground operations there .
On Thursday afternoon Israel's military issued another evacuation warning for swathes of Tyre and surrounding areas .
Israeli airstrikes hit Tyre and Sidon, both southern cities, early Thursday, AFP correspondents said.
AFP footage showed a fireball followed by smoke as a strike hit a building in Tyre's archaeological district.
Resident Ghazouane Halawani told AFP he believed Israel wanted to attack the ancient city's "history and its civilisation".
"We're staying here. This is our country, our land, our life," he added.
Lebanese Foreign Minister Youssef Raggi said on X that he had begun "intensive diplomatic contacts" after Israeli attacks on Tyre struck "its historic old neighbourhoods, churches, mosques, and cultural landmarks that have stood resilient for thousands of years". Israeli soldier killed Lebanon's health ministry said a strike in Tyre killed two Syrians including a child, and another in Sidon killed five people, including two women.
An AFP correspondent said the Sidon raid destroyed the first two floors of a residential building.
The ministry said another strike hit a vehicle in south Lebanon's Adloun, killing six people "including two children, their mother and their father".
Lebanon's military said another strike killed a soldier "while he was driving" in the Nabatieh region.
The state-run National News Agency (NNA) also reported Israeli strikes in other areas of south Lebanon.
Israel's military said a soldier was killed on Wednesday by a Hezbollah drone near the border.
Lebanon was drawn into the Middle East war in early March, after Hezbollah fired rockets into Israel in response to the US-Israeli assault on Iran, which killed the likes of Supreme Leader Ayatollah Ali Khamenei and Secretary of the Supreme National Security Council, Ali Larijani.
Iran has insisted any agreement to end the broader conflict must apply to Lebanon.
On Thursday, the United States and Iran accused each other of violating their ongoing truce following an exchange of fire.