Eyewitnesses in Beirut reported Israeli warplanes flying over the city's southern suburb and conducting several rounds of bombings within an hour in the Dahieh district.

Prior to the attacks, Israeli military spokesman Daniel Hagari said in a statement that the targeted weapons included "a range of coast-to-sea missiles originating from Iran."

The strikes followed earlier Israeli airstrikes on Hezbollah's main headquarters in Dahieh, which killed at least six people and injured 91 others, reports Xinhua, quoting Lebanon's MTV TV channel.

Israeli media suggested that the strikes may have targeted Hezbollah leader Hassan Nasrallah, though his status remains unclear.

Hagari confirmed on Friday that the airstrikes were aimed at Hezbollah's headquarters, which he said were located beneath residential buildings.

The attacks came shortly after Israeli Prime Minister Benjamin Netanyahu addressed the United Nations General Assembly in New York. Netanyahu's office said he approved the airstrike earlier Friday from his hotel and decided to return to Israel ahead of schedule.

At the UN, Netanyahu ruled out an immediate truce in the escalating conflict with Lebanon and warned of threats from Iran, suggesting Israel faces multiple fronts of conflict organised by Tehran.

"We will not back down in the face of threats from Tehran or its proxies," Netanyahu told the assembly, defending Israel's actions as necessary for national security.

Following the Israeli attack, Hezbollah claimed responsibility for an attack on Safed, a city in northern Israel, late Friday.

In a statement, the group said the attacks were "in support of our steadfast Palestinian people in the Gaza Strip and defence of Lebanon and its people, and in response to the barbaric Israeli invasion of cities, villages, and civilians."

Israeli state-owned Kan TV news reported two direct hits on a building in Safed, with no casualties reported. The Israeli military later announced new airstrikes in southern Lebanon and "deep in the country," targeting rocket launchers and weapons storage facilities.

"The IDF continues to attack, damage, and degrade the capabilities and military infrastructure of the terrorist organisation Hezbollah," the IDF declared in a statement.

Iranian President Masoud Pezeshkian condemned the Israeli airstrikes on Dahieh as a "flagrant and unconceivable war crime," according to Iran's official news agency IRNA.

Pezeshkian said Israel's actions against the Palestinian and Lebanese people underscore the international community's failure to halt what he termed "state terrorism," characterising Israel as the "biggest threat" to regional and global peace and security.

Israel has intensified its airstrikes across Lebanon since Monday, marking the most extensive military action in the region since 2006.

Lebanon's health ministry reported nearly 700 deaths due to the strikes this week, and the International Organization for Migration estimated that over 200,000 people have been displaced in Lebanon since last October when Hezbollah began firing rockets into northern Israel in solidarity with Hamas.