Hasan Nasrallah, the leader of Hezbollah, says the killing of Hamas’s powerful deputy leader will “not go unpunished”.
Saleh al-Arouri died in a drone attack in Beirut on Tuesday but Israel has not confirmed it was responsible.
Nasrallah described Arouri’s death as a “major, dangerous crime about which they cannot be silent”.
He added that if Israel wages war on Lebanon “there will be no ceilings, no rules” to Hezbollah’s response.
He previously said that any killings in Lebanon would be a red line.
The attack that killed Arouri was the first in Beirut following months of exchanges of fire between Iranian-backed Hezbollah and Israel, in response to the war in Gaza.
