Israel's air force carried out an airstrike on the Choueifat area on the edge of Beirut's southern suburbs on Thursday afternoon, the Israeli military said, further straining a fragile ceasefire a day ahead of crucial negotiations in Washington.

The strike hit an apartment building. Videos from Choueifat, close to Beirut's international airport, showed white smoke billowing from a residential neighborhood.

Five people were killed and 21 others wounded overnight when an Israeli drone struck an apartment building in the southern city of Sidon where some displaced families lived, the first such attack on Sidon during the latest escalation.

The attack likely came in response to a drone attack that killed a female Israeli soldier in north Israel. LBCI television had reported that Israel had informed the U.S. of its intention for escalation after the attack.

The reason the Israeli army has not carried out an attack in Beirut and its southern suburbs despite the latest escalation is an "American veto," unnamed sources told Israeli newspaper Yedioth Ahronoth on Wednesday.

Israeli forces have begun operating beyond their so-called "Yellow Line" in south Lebanon, which runs around 10 kilometers (six miles) deep inside Lebanese territory, a military official confirmed to AFP on Tuesday.

Since a ceasefire was reached in April, the Lebanese capital of Beirut has been spared from strikes, except for one strike on its suburbs.

But Israel's latest moves have caused fear, urging residents of Dahieh to evacuate once again, after Israeli Prime Minister Benjamin Netanyahu said that he had authorized more intensive strikes targeting Hezbollah across Lebanon.

President Joseph Aoun on Tuesday greeted the Lebanese people in general, and Muslims in particular, on the occasion of Eid al-Adha, wishing that this holiday would bring "peace, hope, and better days for Lebanon and its people."

Grand Mufti Sheikh Abdul Latif Daryan, Lebanon's most senior Sunni cleric, has thrown his support behind the Lebanese state and strongly criticized Hezbollah over the 2024 and 2026 wars with Israel.

On the centenary of the Lebanese constitution, Hezbollah stated that "the Lebanese people stand at a crucial juncture in a highly sensitive domestic and regional moment" that "necessitates, more than ever, adherence to the Lebanese constitution, as amended by the Taif Agreement, as the binding framework for regulating disputes among the Lebanese, managing their state's affairs, and preserving their unity and sovereignty."

Israel's military has called up more troops to Lebanon, an Israeli security official said.

The official, who spoke on condition of anonymity in line with regulations, said Tuesday the military had called up an additional battalion to Lebanon, hours after Israeli Prime Minister Benjamin Netanyahu said he had authorized more intensive strikes across Lebanon.

Israel's military clashed with Hezbollah Tuesday along a strategic river in Lebanon as Israeli troops tried to push farther north, just three days before Lebanese and Israeli military delegations are set to meet for direct talks in Washington.

A previously reached ceasefire appeared more nominal by the day, complicating efforts at a broader peace in the Iran war, as Tehran wants an end to the fighting to include Lebanon.