Israel conducted on Monday its first strike in the Lebanese capital since it launched an operation to secure its northern border, killing three members of a Palestinian militant group, according to their organisation.
Israel, which has not yet commented on the strike, launched a wave of air strikes on Lebanon last week, mainly targeting strongholds of Iran-backed Hezbollah.
On Friday it dealt Hezbollah a seismic blow by killing its chief, Hassan Nasrallah.
The strikes have killed hundreds and forced hundreds of thousands more to flee their homes, and left people across crisis-wracked Lebanon and the wider region fearful of more violence to come.
Most of Israel's strikes over the past week have targeted Hezbollah strongholds in eastern and southern Lebanon and the southern suburbs of Beirut, the main bastion of the group.
On Monday, a drone strike on a building in Beirut's busy Cola district killed three members of the Popular Front for the Liberation of Palestine (PFLP), the leftist armed group said.
Lebanon's health ministry also reported the strike, saying it had killed four people and wounded four others.
Israel has not commented on the strike.
"I woke up to the sound of people screaming that a place near the pharmacy had been targeted, and I rushed there to make sure the employees were OK," said Marwa al-Jamal, who owns a chemist's in the neighbourhood.
Mohammed al-Hoss, another resident of the area, said the strike had damaged his house, and that people displaced by the bombing elsewhere in the country had been seeking shelter there.
"The kids were in shock... I didn't think we'd reach this stage where we are being targeted unjustly for something we have nothing to do with," the 41-year-old said.
Hours after the Cola strike, Palestinian Islamist group Hamas announced that its leader in Lebanon, Fatah Sharif Abu al-Amine, had been killed along with his wife and two children in another strike on Al-Bass refugee camp in south Lebanon.
The Israeli military announced the launch of more strikes on dozens of Hezbollah targets in Lebanon's Bekaa region in the east of the country.
Israel "will continue to attack powerfully, damage and degrade Hezbollah's military capabilities and infrastructure in Lebanon", the army said in a statement on Telegram.
AFP journalists in Beirut heard drones flying over the Lebanese capital throughout Sunday.
Hezbollah began low-intensity cross-border strikes on Israeli troops a day after its Palestinian ally Hamas staged its unprecedented attack on Israel on October 7, triggering war in the Gaza Strip.
Israel said earlier this month that it was shifting its focus from Gaza to securing its northern border with Lebanon, in order to allow Israelis displaced since October by the violence to return to their homes.
On Sunday, Israeli strikes killed 105 people in Lebanon, according to the Lebanese health ministry, which also said 359 others had been wounded.
Lebanon's Health Minister Firass Abiad said Saturday that 1,030 people including 87 children had been killed since September 16.
UN 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.
Prime Minister Najib Mikati said up to one million people may have been uprooted, in potentially the "largest displacement movement" in Lebanon's history.
The violence in Lebanon has raised fears of a much wider conflagration in the region.
On Monday, the Israeli army said it "successfully intercepted a suspicious aerial target that crossed from Lebanon into Israeli territory".
Israel said it also carried out strikes in Yemen on Sunday, targeting Iran-backed Huthi rebel positions.
Huthi media reports said those strikes killed four people and wounded 33.
The raids in Yemen came a day after the Huthis said they launched a missile at an Israeli airport, trying to hit it as Prime Minister Benjamin Netanyahu was returning from New York.The Israeli military has said its operations in Lebanon aim to eliminate Hezbollah's leadership and capacity to attack Israel.
It said the air strike that killed Nasrallah on Friday also "eliminated" another 20 Hezbollah members, including senior leaders.
Hezbollah on Monday confirmed that Israel also killed Nabil Qaouq, a member of the group's central council, in a Beirut strike on Saturday.
Analysts told AFP Nasrallah's death leaves a bruised Hezbollah under pressure to respond.
Lebanon began a three-day national mourning period for Nasrallah on Monday, with flags to fly at half-mast on public buildings.
Hezbollah's deputy chief Naim Qassem is due to deliver an address later Monday.
Iran has said Nasrallah's killing would would bring about Israel's "destruction".
In Israel, some had mixed feelings about the killing.
"Nasrallah was responsible for the deaths of many Israelis, so it is good news," said Matan Sofer, 24, in the northern town of Rosh Pina."But do we risk it getting worse, who knows?" he said.
World leaders have called for a de-escalation.
French Foreign Minister Jean-Noel Barrot met with Prime Minister Mikati in Beirut on Sunday, and said his government sought "an immediate halt" in the strikes.
He is the first high-level foreign diplomat to visit since the Israeli strikes intensified.
US President Joe Biden, whose government is Israel's top arms supplier, said Sunday a wider war "really has to be avoided".
In Gaza, AFP journalists said the number of air strikes across the territory has dropped significantly in recent days, particularly since Nasrallah's killing on Friday.
Hamas's unprecedented October 7 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.
Of the 251 hostages seized by militants, 97 are still held in Gaza, including 33 the Israeli military says are dead.
Israel's retaliatory military offensive has killed at least 41,595 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.