BEIRUT: Hezbollah chief Hassan Nasrallah warned Israel Wednesday against waging war on Lebanon, a day after a strike blamed on Israel killed Hamas's number two in the group's southern Beirut suburbs stronghold.

"If the enemy thinks of waging a war on Lebanon, we will fight without restraint, without rules, without limits and without restrictions," Nasrallah said in a televised speech.

"We are not afraid of war," he said, adding that "for now, we are fighting on the frontline following meticulous calculations".

Lebanese authorities and Hamas accused Israel of killing Salah al-Aruri in Beirut's southern suburbs on Tuesday with six others.

Israeli army spokesman Daniel Hagari did not directly comment on Aruri's killing but said the military was "highly prepared for any scenario" in its aftermath.

Israeli strikes on Lebanon had largely been limited to the border area before Aruri's killing, with Hezbollah and its arch-foe exchanging near-daily fire after the Israel-Hamas war broke out on October 7.

The attack sparked fears of a broader conflagration because Aruri is the most high-profile figure to be killed since fighting in Gaza began in October, and his death came in the first strike on the Lebanese capital since hostilities started.

Nasrallah described the attack as a "major and dangerous crime" which "will not go unanswered and unpunished" -- repeating a threat made by Hezbollah on Tuesday.

The group announced several strikes on Israeli troops and positions Wednesday, within the usual scope of the border area.

"Israel has been weakened" by Hamas's October 7 onslaught, Nasrallah said, adding that the country was "now on the path to extinction".

Nasrallah spoke in a pre-planned speech commemorating Iran's Islamic Revolutionary Guards Corp general Qasem Soleimani four years after his death in a US strike in Iraq.

He is set to deliver another televised speech on Friday.

Earlier Wednesday, a high-level Lebanese security official said that Israel fired guided missiles from a warplane to kill Aruri in a Beirut suburb.

Hamas said Aruri would be buried on Thursday in Beirut's Shatila Palestinian refugee camp.

Since hostilities began, 170 people have been killed on the Lebanese side, most of them Hezbollah members but also more than 20 civilians including three journalists, according to an AFP tally.

On the Israeli side, at least four civilians and nine soldiers have been killed, according to figures from the military.